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Kelompok 2:
1. Khoirinisak
2. Riski Yudatama
3. Harlely Rianavita
4. Seri Dwiwati
5. Tria Yussanti
, Molecules and Ions
1.1 Basic competencies
Explaining the concept of atoms, theori of atoms, structure atoms, mass number
atoms, elektron configuration, periodic table unsure
1.2 Indicator
Comparing the development of atomic theory
Determine the number of protons, electrons and neutrons of an element by its
atomic number and mass number.
Determine the isotope, Isobars and isoton an element
Determining the atomic structure based on the periodic table
Determine the properties of elements relative atomic mass
Determine the valence electron and the electron configuration of elements
from the periodic table
ATOMS
1.1. Particle Concept
Sand is one example of the object in the form of granules. However, a grain of sand
can still be broken down and keep the sand fractions. Imagine a grain of sand with a
mass about 10 mg (regular sand grains) if grains of sand were split into two, you will
get two grains of sand, each mass of 5 mg. If each grain is broken up into two more,
then 4 grains of sand will be obtained each 2.5 mg mass. Suppose that the cleavage
can be carried out continuously, it will obtain a very small grains, but still the same
with sand. So is the smallest particle of matter is part of the material still has
properties similar to those materials.
ATOMS
Sand sand particles called molecules. Sand molecules composed of one silicon atom
bonded with two oxygen atoms. This molecule can also be broken down, but the
results are no longer the sand, but two types of atoms, ie atoms of silicon and oxygen
atoms. Oxygen atom is the smallest part of the oxygen that still has the same
properties with oxygen. Likewise with the silicon atom is the smallest piece of silicon
that still has the same properties with silicon. Oxygen and silicon is the substance that
was in the form of atomic particles.
1.2 THEORY ATOMS
1.2.1 Democritus
In the fifth century SM, Greek philosopher Democritus expressing his belief that
all matter consists of particles of very small and can not be on for longer, which he
calls atomos (can not be shared). This opinion is rejected by Aristotle (384-322
BC), who argued that matter is continuous (the material can be cut continuously
until no finite). But this theory remained, at that time experimental evidence
supports the concept of "atomism" is and gradually produce a modern definition of
elements and compounds.
1.2.2 John Dalton (1803)
In 1803, John Dalton expressed the opinion expressed about the atom. Dalton
expressed the opinion of the atoms as follows:
1. The element is composed of very small particles, called atoms. all the atoms of
certain elements is the identity, which has the size, mass and chemical properties
of the same. Certain elements of different atoms with atoms of other elements.
2. compound consists of atoms of two elements or more. In each compound the
ratio between the number of atoms of any two elements there can be an integer or
simple fraction.
3. chemical reactions that occur in just a separation, merger, or rearrangements of
atoms; so that the atoms can not be created or destroyed.
Hypothesis Dalton atomic model as illustrated by solid balls as in shot-put. As the
picture below:
1.2.3 Josep John Thomson (1900)
Based on the discovery of a better cathode tube by William Crookers, then JJ
Thomson further research on cathode rays and can be ascertained that the cathode
rays are particles, because it can turn a propeller that is placed between the cathode
and anode. From the results of this experiment, Thomson stated that cathode rays
are particles making up atoms (subatomic particles) which are negatively charged
and hereinafter referred to as electrons.
Atoms are neutral particles, because negatively charged electrons, then there must
be other positively charged particles to neutralize the negative charge of the
electron. From these discoveries, Thomson improve weaknesses of daltons atomic
theory and atomic theory put forward known as Thomson Atomic Theory. Which
states that:
"Atom is a solid ball is positively charged and negatively charged electrons
scattered therein"
Thomson atomic model analogous to the positive ball solid. Thomson atomic
model can be described as follows
1.2.4 Rutherford
Rutherford with two of his disciples (Hans Geigerdan Erners Masreden)
conducted an experiment known as the scattering of alpha rays (λ) of thin plates
of gold. Previously been found to the alpha particle, the particle is positively
charged and move straight, large translucent power so it can penetrate thin sheets
of paper. The experiment was actually intended to test the opinion of Thomson,
namely whether this atom is a ball really solid when subjected to a positive alpha
particles will be reflected or deflected. From their observations, found the fact
that when alpha particles were fired at a very thin gold plate, then most of the
alpha particles passed (there is a deviation angle of less than 1 °), but from the
observations obtained Marsden fact that one in 20,000 alpha particles will turn
angle of 90 · Even more.
Based on the symptoms that occur, obtained following conclusions:
1. Atom is not a solid ball, because almost all the alpha particles passed
2. If the gold plate is considered as a single layer of atoms of gold, the gold
atoms contained in very small particles which are positively charged.
3. Such particles are particles that make up an atomic nucleus, based on the fact
that 1 in 20,000 alpha particles will be deflected. When the ratio of 1:20,000 is a
comparison of the diameter, the size of the nuclei obtained approximately 10,000
smaller than the overall size of the atom.
Based on the facts obtained from this experiment, Rutherford proposed a model
of the atom, known as Rutherford Atom Model which states that the Atomic
nuclei are composed of very small and positively charged, surrounded by
negatively charged electrons. Rutherford assumed that the particles contained in
the nuclei of neutral particles binding function of positive order not to repel each
other.
Rutherford atomic model can be described as follows:
1.2.5 Neils Bohr
1913, Danish physicist named Neils Bohr atom Rutherford repair failures through
experiments on the hydrogen atom spectrum. Bohr on atomic hydrogen involves a
combination of the classical theory of Rutherford and of Planck's quantum theory,
expressed by four postulates, as follows:
1. There are only a certain set of orbits are allowed for one electron in a hydrogen
atom. Orbit is known as a state of stationary motion (settling) of electrons and is a
EXERCISE
circular path around the core.
2. As long as the electrons are in stationary trajectory, the electron energy remains
so there is no energy in the form of radiation emitted or absorbed.
3. Electrons can only move from one stationary trajectory into another stationary
trajectory. In this transition, a certain amount of energy involved, the amount in
accordance with Planck equation, ΔE = hv.
4. Stationary trajectory is allowed to have the scale with certain properties,
especially a property called angular momentum. The amount of angular
momentum is a multiple of h/2Π or nh/2Π, where n is an integer and h Planck
constant.
According to Bohr's atomic model, the electrons surrounding the nucleus in certain
paths called electron shells or energy levels. Lowest energy level is the electron
shell which is located in, getting out of her skin and the greater the number the
higher the energy level.
1. How the atomic theory by John Dalton,?
2. Describe the atomic model according to what jj thomson.dan particles arranged?
3. What is the difference borhdan atomic theory atomic theory of quantum
mechanics?
Quiz
In this section you have mastered the competencies is to know the type and model
type of atomic theory and structure of an atom. based on the description of the
various experiments the scientists in search of something that make up atoms.
complete the following table!
Summary of events and personalities
involved
The results obtained
- Use of the term atomic
- The mass of the electron
John dalton atomic theory put forward -
Gold plate experiment -
- Bohr's atomic model
- The discovery of the neutron
1.3 ATOMS STRUCTURE
massa (kg) Massa relatif Muatan listrik (C)
Proton 1,672623×10-27 1836 1,602189×10-19
Neutron 1,674929×10-27 1839 0
Electron 9,109390×10-31 1 -1,602189×10-19
1.3.1 Elektron
Electrons are found through the cathode tube experiment was first performed by
William Crookes. Joseph John Thomson (1897) continue the experiments of William
Crookes that the influence of electric field and magnetic field in the cathode ray tube.
In the experiment, when the two metal plates connected by a high voltage source,
negatively charged plate called the cathode, which emits invisible light. cathode ray is
attracted to the positively charged plate, called the anode, where the rays iti going
through a hole and climb on to the other end of the tube. When these rays hit the
surface that has been coated in particular, the cathode ray luminescence yield strong
or bright light.
Because the cathode ray is attracted by positively charged plate and was rejected by
the negatively charged plate, the ray must consist of particles are negatively charged.
These negatively charged particles that is what we know as electrons.
1.3.2 Proton and nucleus
The discovery of the proton beam is a continuation of the cathode ray tube (CRT). Its
positive pole away from those found by Goldstein in 1886. And supported by the
Rutherford prediction.
Rutherford conducted experiments using α-rays to determine the atomic structure, α-
rays by firing a very thin gold leaf. Then he observed that most of the particles
penetrate the sheet without turning or only slightly banked. He also observed that
there is a waste of α particles (or dibelokan) with a large angle. On several occasions,
returned towards the coming of α particles.
To explain the results of light scattering experiment, Rutherford made a new
model for the structure of atoms, assuming that most of the atom must be empty
space. He also predicted that the positive charge accumulated in the nucleus of all
atoms b (nucleus), which is a dense central core of which lies within the atom.
The particles are positively charged protons in the nucleus is called. In a separate
experiment, found that the proton has a charge yiap magnitude (large) the electron
and its mass equal to 1.67262 × 〖10 〗 ^ (-24).
1.3.3. Neutron
Rutherford atomic model leaves important issues unresolved. when comparing the
mass of hydrogen that has one proton with a mass of helium has 2 protons. So the
ratio of the mass of hydrogen atoms with helium atoms is 2:1. But in reality its mass
ratio of hydrogen atoms with helium atoms is 4:1.
Rutherford and his colleagues postulated that there must be other types of subatomic
particles in atomic nuclei; proof is given by James Chadwik, in 1932. When Chadwik
α particles fired into a thin sheet of beryllium, the metal emits a very high-energy
radiation similar γ-ray view. Subsequent experiments showed that the light is actually
composed of neutral particles that have a mass slightly larger than the proton
mass. Chadwik named this particle the neutron.
Mystery of the mass ratio of hydrogen atoms with an atomic mass of helium can
already be described. In the helium nucleus has two protons and two neutrons,
whereas in the hydrogen nucleus there is only one proton only. So that the mass ratio
of hydrogen atoms into helium atoms with a mass of 4:1
1.4 Number of atoms and Number of mass
The number of protons in an atom is called the atomic number or proton number. The
number of protons are characteristic of an element. This means that the atoms of a
particular element has an atomic number that distinguishes it from atoms of other
elements. Given the symbol Z. The atomic number For neutral atoms the number of
protons in the nucleus is equal to the number of electrons so the atomic number is
also the number of electrons that orbit around the atomic nucleus. The number of
protons and neutrons in atomic nuclei is called the mass number, which given the
symbol A. So, if the atomic symbol is X then the writing of an atom is:
XZA
Description:
X = the atomic symbol
Z = atomic number = number of protons = number of electrons
A = mass number = number of protons + number of neutrons.
or
Number of mass (A) =total of protons + total of neutron
Total of neutron = number of mass – number of atoms
EXAMPLE
Atoms having the same atomic number but have different mass numbers called isotopes. Examples of isotopes:
Each isotope of an element have the same chemical properties as the number of electrons equal. These isotopes can be used to determine the relative atomic mass (Ar), the atom is based on isotopic abundance and atomic masses of all isotopes.
Isobars are elements that have the same mass number. The existence of isotopes that make the Isobars.
Isoton are atoms that have equal numbers of neutrons but different number of protons. As we have learned before, that the neutron is the difference between the number of atomic mass number; then isoton can not occur for the same element.
1. How many protons, electrons, neutrons, atoms following the
a. 12 6 c b. 23
11 N+
2. An atom has 19 protons 20 neutrons and 19 electrons. What the numbers and atomic numbers? What is the cargo?
Solution :
1. a. Atom 12 6 C
Number of atoms : total proton : total elektron : 6
Number of mass : 12
Number of neutron : 12-6 :6
So,total proton : 6,
Total elektron : 6 ,
Total neutron,:12
b.Atom 23 11
N+
Number of atoms : total proton :total elektron : 11
Number of mass : 23
Total of neutron : 12
Total elektron :Z-muatan :11-1:10
So, ,total proton : 11,
Total elektron : 12
Total ,neutron,:10
2. Number of mass : total proton + total Neutron :19 + 20 :39
Number of atoms : total proton : total elektron : 19
1.5Periodic Table
Periodic systems have evolved along with the increasing number of elements
that are found. Making periodic table preceded by Dobereiner proposed
system triads. Then further developed by Newland with oktafnya system.
Further preparation of the periodic table is done by Lothar Meyer and
Mendeleev. Mendeleev who first suggested the periodic table, then he is
regarded as the inventor of the periodic table is often referred to as short-
periodic system of elements. Moseley managed to find errors in the
Mendeleev periodic table there is an inverse element is located.
Modern periodic system can be regarded as Mendeleev periodic system
improvements. Modern periodic system, also known as long-form periodic
system, composed of increasing atomic number and similarity of properties.
In the modern periodic system, there are horizontal rows called periods and
vertical columns called groups. Periodic system has to do with the electron
configuration. Group together with the valence electrons and period equal to
the amount of skin atom.Unsur elements that make up the periodic system
have kelogaman properties. In general, these elements exist that have the
properties of metals, non metals, and metalloids. If we look at the periodic
table, metal elements located on the left, and non-metallic elements located on
the right. The properties of the periodic system, among others, atomic radii,
EXERCISE
which have a tendency in one group is getting bigger and smaller in one
period. This is the opposite of ionization energy, electron affinity, and
electronegativity that have a tendency in one group gets smaller and in a
period greater
1. periodic structure based on modern
a. chemical properties of elements
b. the atoms of the element
c. physical properties of elements
d. electron configuration
e. atomic weight of element
2. atom consists of positively charged material that was scattered electrons in
electron bagaiakan raisins in bread kismis.model atoms was presented by
a. R. Milikan
b. jj Thomson
c. N, Borh
d. Goldsten
e. E, Rutherford
3. atomic nuclei proposed by
a. jj Thomson
b. E, Rutherford
c. Goldsten
d. H. Begruerel
e. marie curie
4. elements are elements that the said group how
a. 1A
b. 11A
c. 111A
d. 1VA
e. VA
5. what is the atomic number elements of potassium
a. 4
b. 8
c. 19
d. 38
e. 58
6. the number of atoms of element X that its nucleus contains 20 neutrons while
the X + ion contains 18 electrons
a. 18
b. 20
c. 38
d. 39
e. 40
7. known 6530Zn Zn 2 + ions mengndung
a. 28 electrons in the core
b. 28 protons in the nucleus
c. 28 protons around the core
d. 8 electrons around the nucleus
e. 30 protons around the core
Electron configuration and valence electron
8. A period of 31 numbered element has the electron configuration as follows
K L M
2 8 5
Each atomic element has
a. 15 electrons 15 neutrons
b. 15 protons 15 neutrons
c. 15 protons 16 neutrons
d. 15 electrons 31 neutrons
e. 31 electrons 31 protons
9. Here is the symbol of an element 20A
Electron configuration for the A2 + ion is
a. 2 8 8 2
b. 2 8 10
c. 2 8 8
d. 2 8 8 4
e. 2 8 12
10. The number of valence electrons in the 54X is
a. 4
b. 5
c. 6
d. 7
e. 8
ESAI1. explain the Rutherford atomic model. particles of what is found Rutherford
2. specify the period and class of each element below
a. 8o
b. 10Ne
c. 17Cl
d. 20Ca
e. 11Na
3. A third of an atom has an atomic number 53 and number 129 times
a. Make the filling electron configuration then draw each skin electron
b. How many valence electrons
c. Berapakan isotopes, Isobars, and isoton atom A is!
1.6 Electron Configuration
Persebaran elektron dalam atom disebut konfigurasi elektron. Persebaran
elektron pada kulit-kulit atom mengikuti pola tertentu.
Pengisian elektron dimulai dari kulit K, L, dan M
1.6.1 Relationship between the electron configuration with Period
In the periodic system, the period shows the number of skin that has been filled
electron in an atom.
So according to the amount of skin that is K, L, M, N, O, P, Q then the periodic
system has seven periods.
1,6,2 Relationships Between Group With Electron Configuration
Element which is located on one group has chemical properties that are
similar (almost identical).
The elements of class A is called the primary group, while the elements of
group B is called a transition element (transition), all elements of the
transition given the symbol B triads except for iron, palladium and platinum
are called "class VIII''
1.6.3 SYMBOL ELEMENTS OF GROUP A
Coat Type NAME TYPE Configuration Elektron outer Orbital
I - A Alkali ns1
II - A Alkali tanah ns2
III - A Boron ns2 - np1
IV - A Karbon - ns2 - np2
Silikon
V - A Nitogen - Posphor
ns2 - np3
VI - A Oksigen ns2 - np4
VII - A Halogen ns2 - np5
VIII - A Gas mulia ns2 - np6
SYMBOL ELEMENTS OF GROUP B
Elektron Configuration
Coat Type
(n - 1) d1 ns2 III - B(n - 1) d2 ns2 IV - B(n - 1) d3 ns2 V - B(n - 1) d4 ns2 VI - B(n - 1) d5 ns2 VII - B(n - 1) d6-8 ns2 VIII(n - 1) d9 ns2 I - B(n - 1) d10 ns2 II - B
1.6.4 Determination Period And How To Type A Elements
1. The element with atomic number 11, the configuration: 1s2 2s2 2p6 3s1
- N = 3, means a period of 3 (skin M).
- Valence electrons (outermost) 3s as much as an electron, means including
class IA.
2. Ga elements with atomic number 31, the configuration: 1s2 2s2 2p6 3s2
3p6 4s2 3d10 4p1
- N = 4, means the period 4 (skin N).
- Elektronvalensi 4s2 4p1, meaning class IIIA.
3. Sc element with atomic number 21, the configuration: 1s2 2s2 2p6 3s2 3p6
4s2 3d1
- N = 4, means the period 4 (skin N).
EXERCISE
- 3d1 4s2 means the group IIIB.
4. Fe element with atomic number 26, the configuration: 1s2 2s2 2p6 3s2 3p6
4s2 3d10
- N = 4, means the period 4 (skin N).
- 3d6 4s2, means the group VIII.
A. Choose one correct answer!
1. Nucleus of an atom consists of .......
a. protons and neutrons c. protons, electrons and neutrons
b. protons and electrons d. neutrons and electrons
2. Atom will become positive ions or cations when .......
a. receiving proton c. loss of proton
b. accept electrons d. loss of electrons
3. Atom consists of positively charged material and the electrons are scattered
Inside. This is a model of the atom by .......
a. John Dalton c. Thomson J.J
b. Rutherford d. Niels Bohr
4. An atom has three orbits of the electrons with the number of electrons in the
outermost orbit 2 electrons. Element's atomic number is .......
a. 8 b. 12 c. 14 d. 16
5. What is meant by the atomic number is .......
a. the number of protons in the nucleus
b. the number of electrons in atomic nuclei
c. number of neutrons in atomic nuclei
d. the number of protons and neutrons
6. The number of neutrons contained in the atom 2311Na is .......
a. 6 b. 8 c. 10 d. 12
7. Distribution of electrons in an atom is called .......
a. elektronisasi c. electron configuration
b. ionization d. isotope
8. Ion consisting of two or more atoms is called .......
a. cation c. polyatomic
b. anion d. single ion
9. These particles are not electrically charged is .......
a. protons c. electron
b. atom d. ion
10. Of the following chemical formula that considered the molecular compound is
.......a. H2 b. O3 c. CO d. P4
B. Answer the questions below with a brief and clear!
1. According to Democritus, the material is discontinuous, explain what it
means!
Answer:.......................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
2. Atom consists of protons, electrons and neutrons. How does the layout of the
subatomic particles in atoms?
Answer::.....................................................................................................................................
..................................................................................................................................................
..................................................................................................................................................
3. Write the electron configuration of elements with atomic numbers
a. 7 b. 14 c. 18
Answer:....................................................................................................................................
Standard Competens : 3. Discribing about Ions
Indicator : Distinguish between the anion and cation charge
..................................................................................................................................................
IONS Ion is an atom or group of atoms that have a positive or negative net charge. The number of positively charged protons remain the same preformance of an atom, but the number of negative charged electrons can be increased or decreased. Neutral atom loses one or more of its electrons will produce a cation, ion with a positive total charge. For example, atoms (Na) can easily lose its one electron to become kationn sodium, which recorded for Na +.
Atom Na Ion Na+
11 proton 11 proton11 elektron 10 elektron
On the other hand, the neutral atoms receive electrons will produce an anion, the total negative ion charge due to the addition of the number of its electrons. for example, atomic chlorine (Cl) may receive an additional electron to become ions clorida.
Atom Cl Ion Cl-
17 proton 17 proton17 proton 18 elektron
Atoms can lose or receive more than one electron. For example, Mg2+, Fe3+ and others. These ions also Na+ and Cl- can be called monatomic ions because only composed of one atom. While ion consisting of two or more atoms in the polyatomic ion called. Such as, OH-, NH4
+ , CN- and others.
Ionic Formulas compound
Ionic compound is a compound formed by cations and anions. For example NaCl is
composed of ions Na + and Cl-ions. In order for ionic compounds are electrically
neutral, the amount of charge on the cations and anions in each unit of the formula
must be zero. If the charge on the anions and cations are different, we apply the
EXAMPLE
exerciseESAI
following rules to create electrically neutral formula: cations subscript numbers equal
to the charge on the anion, and the numbers subscript equal to the charge on the
anion-cation.
Potassium Bromide k + cations and the anions Br-ionic compounds combine
to form potassium bromide. The amount of the charge is +1 + (-1) = 0, so it is
not in need subscript. The formula KBr.
Zinc Iodide Zn2 + cations and anions I-combine to form zinc iodide, the
amount of the charge +2 + (-1) = +1, so that the charge be zero we must
multiply charge anions-1 by 2 and adding the subscript 2 on iodine. So the
formula for ionic zinc iodide is ZnI2.
Aluminum Oxide Al3+ dan anion O2- -joined to form aluminum oxide, the
charge +3 + (-2) = +1, in order to charge the non-2 (+3) +3 (-2) = 0 and add
subskrit 2 on Al , the subscript 3 on O.
1. Among the following properties are not properties of ionic compounds are .... A. fragile B. high melting point C. the solution can deliver electricity D. lelehannya can deliver electricity E. the solid can deliver electricity
2. Among these substances, which have an ionic bond is .... A. ice B. limestone C. silicon D. sugar
E. bronze
3. Na atoms with atomic numbers 11 to form the ion ... . A. +1 B. -1 C. +2 D. -2 E. +3
4. An element with atomic number 12 can form ionic bonds with atoms unsurbernomor ... . A. 3 B. 18 C. 11 D. 20 E. 17
5. Electron configuration of element X with 2, 8, 8, one can form ionic bonds with elements Electron configuration ... . A. 2, 8, 1 B. 2, 8, 2 C. 2, 8, 7 D. 2, 8 E. 2
6. Most ionic bond can form between pairs of elements ... . A. K and F B. Li and C. C. Na and Cl D. Na and Li E. K and Mg
7. Here are the properties of ionic compounds, except ... . A. water-soluble C. soft and fragile B. can conduct electricity of melt D. the solution can conduct electricity E. high melting point
8. The couple elements - elements of the following groups that can form an ionic bond is an element of class .... A. IA & VIIIA B. B. IA & IIA
C. C. IIA & VIIA D. VIA & VIIA E. IIIA & IIIA
9. The following pairs of compounds which have an ionic bond is .... A. KCl & CaF2 C. CaF2 & HF E. NH3 & KNO3
B. NaCl & CCl4 D. KCl & CCl4
15. Each element of X & Y - each having 6 & 7 electrons. Formulas & type of the corresponding bond if both element is .... A. XY6, ionic B. X2Y, covalently C. XY2, covalently D. XY2, ionic. E. X2Y, ionic
16. The following pairs of compounds that bind covalently coordinate ion & is .... A. NaCl & CO2 B. SO2 & CCl4 C. NaCl & HCl D. NH4
+ & MgCl2 E.. KOH & O2
17. Type of bond that is not likely to occur between non-metallic & non-metal is ... . A. Ionic bond C. Single covalent bond B. Triple covalent bonds D. Coordinate covalent bond E. Double covalent bond
18. Statements are true about an ionic bond is .... . A. Occurs between the elements in group VIIA & VA D. Occur with the use of electron B. Have an electrostatic attraction force E. Can draw objects - metal objects C. Having a small electron negativity difference
19. 11Na & 35Br elements can form .... . A. Ionic bonding, the formula Na2Br D. Ionic bonding, the formula NaBr B. Covalent bonding, the formula NaBr E. Covalent bonding, the formula Na2Br C. Covalent bonding, the formula NaBr2
20. The following group of compounds that have ionic bonds are .... A. H2O, CO2, CH4 D. CO2, CH4, NH3
ESAI
B. . NaCl, HI, H2O E. K2O, NaBr, MgCl2
C. HCl, H2SO4, NaOH
21. Element with electron configuration 1s2 2s2 2p6 3s2 can form ionic bonds with the elements .... A. 1A B. 4B C. 17C D. 19D E. 20E
22. Among the elements below which has a tendency to accept electrons form a configuration electron is stable ... . A. 10X C. 17Z B. 11Y D. 18A E. 19b
23. The following elements are very difficult to chemically bind is .... A. Fe, Au C. Cl, P B. Na, Mg D. H, He E. Ne, Ar
24. The following statement is not a characteristic ionic bond is .... A. Formed between the metal & non-metallic D. There are positive & negative ions ion B. Has a tensile strength - attractive electrostatic C. Handover occurs electron D. There are positive & negative ions ion E. Occurs between the elements of group IVA & VIA
25. The following group of compounds that have ionic bonds are .... A. H2O, CO2, CH4 D. K2O, NaBr, MgCl2 B. NaCl, HI, H2O E. HCl, H2SO4, NaOH C. CO2, CH4, NH3
Standard Competens : 3. 3. Comparing between molekules unsure dan molekules element.
Indicator :
discribing about molekules comparing between molekules and element Distinguishing unsure and element differentiateing molekules unsure and molekules element.
1.. Determine the ionic compounds formed from reactions between these atoms
a 11Na dan 10S
b. 13Al dan 10S
2. Choose couples the following elements that can form ionic compounds!
a. 19K dan 2He
b. 19K dan 17Cl
c. 16S dan 8O
4. Determine the formula of ionic compound element pairs of the following elements a. Na with O b. Ca with N
MOLEKULESMolecule (molecule) has the same meaning as the compound (compound), which is a
combination of several elements / atoms.
Examples of compounds / molecules that exist in nature such as: water (H2O), carbon dioxide
(CO2), carbon monoxide (CO2), and others.
So, what's different compounds and molecules?
In terms of meaning it makes no difference. But its use is different. Molecules including
nouns (objective) while the compound is an adjective (adjective). Let us see the following
figure:
H2O CO2
H2O
Sentence / statement can be made based on the picture above are:
• In the picture there are two types of compounds, namely water (H2O ) and carbon dioxide
(CO2).
• In the picture there are three molecules, namely two molecules of water (H2O) and one
molecule of carbon dioxide (CO2).
Molecule formation occurs from non-metallic elements which reacted with similar non-
metals, non-metallic element with other non-metallic elements or non-metallic elements with
metal elements
chemical formulaChemists use chemical formulas to express the composition of the
molecular and ionic compounds in chemical symbols. Here we will discuss about the
molecular formula, empirical formulas and formulas of chemical compounds.
molecular formula
Molecular formula shows the exact number of atoms of each element in the
smallest unit of a substance. For example H2 is the formula for the hydrogen
molecule, O2 for oxygen, O3 for ozone, H2O for water and others. Subscript
numbers mark the number of atoms of an element. Molecular formula shows the
exact number of atoms of each element in the smallest unit of a substance. For
example H2 is the formula for the hydrogen molecule, O2 for oxygen, O3 for ozone,
H2O for water and others. Subscript numbers mark the number of atoms of an
element present in the molecule. For example H2O, no subkrip on O because it only
contained one O atom in water molecules, whereas for H subscripts 2 because there
are two H atoms in water molecules.
3.1 Diatomic Molecules
Diatomic molecule is formed from two similar atoms. Are you able to cite the
example of a diatomic molecule? Yes I do.
Examples of diatomic molecules is molecular oxygen, molecular hydrogen and
molecular nitrogen.
3.2 Tetraatomic molecules
Tetraatomik molecule is formed of four similar atoms. Are you able to cite
examples of molecules tetraatomik? Yes I do. Examples tetraatomik molecule is
a molecule of phosphorus.
3.3 Oktaatomic molecules
Oktaatomik molecule is formed from eight similar atoms. Are you able to cite
examples of molecules oktaatomik? Yes I do. Examples tetraatomik molecule is
a molecule of sulfur (sulfur).
Quiz
Fill in the blank in the table of molecular elements in the column name and the number of elements, such as number 1.
NO Unsure name Lambang Rumus Molekul
Compiler Name and Number of Elements
1
2
3
4
5
6
7
8
9
10
11
Hidrogen
Florida
Oksigen
Oksigen
Nitrogen
Klorida
Bromide
Iodide
astatin
phosphor
sulfur
H
F
O
O
N
Cl
Br
I
At
P
S
H2
F2
O2
O3
N2
Cl2
Br2
I2
At2
P4
S8
Consists of two atoms of hydrogen ……………………………………………
……………………………………………
…………………………………………..
…………………………………………….
…………………………………………..
………………………………………….
……………………………………………
…………………………………………
…………………………………………
………………………………………..
3.4 UNSURE
The element is a single substance that can not be described again into other
substances are much simpler with ordinary chemical reactions. The universe contains
countless elements. It turned out that all substances are composed of basic substances
called elements. Inspired by the many elements that exist in the universe is Jons
Jakob Berzelius (1779-1848) who came from Sweden states that any given element
symbol in the form of letters of the name element in the Latin language with the
following provisions:
1. The emblem consists of a single element must use uppercase letters
2. Coat terdir elements of the two letters should be put on the first letter uppercase
and lowercase letters in the second letter
Some element name and symbol
NAMA LATIN
NAMA INDONESIA LAMBANG
Argentum Perak Ag
Aluminium Aluminium AlArgon Argon Ar
Arsenicum Arsen AsAurum Emas AuBorium Boron BBarium Barium Ba
Bismuthum Bismut BiBromium Bromin Br
Carbonium Karbon CCalsium Kalsium Ca
Chlorium Klorin ClCobaltum Kobal CoChromium Kromium Cr
Cuprum Tembaga CuFluorium Fluorin FFerrum Besi Fe
Hydrogenium
Hydrogen H
Helium Helium He
Symbols of the elements listed above is only a small fraction of the elements
contained in this universe.
3.5 Compounds
Compounds are substances that emerged from two or more elements through chemical
reactions. Each compound has unique properties, different from the properties of its
constituent elements. Examples of Hydrogen and Oxygen is a gas, are the combined
results of the second element is the clear liquid, colorless, and no sense that we know as
water.
The compound is a substance that can be used to chemically decompose into substances
that are more modest. Compound composed of two or more elements of different types
with a fixed and certain comparisons with the incorporation of chemically
Compound name and formula of compounds
NAMA SENYAWA
RUMUS SENYAWA
Glukosa C6H12O6
Sukrosa C11H22O11
Garam Dapur
NaCl
Asam Cuka CH3COOHUrea CO(NH2)2
Asam Sulfat
H2SO4
Soda Kue NaHCO3
Amoniak NH3
Aseton CH3COCH3
The molecule is a particle consisting of two or more atoms, either type of atom or
different atoms. The molecule consists of molecules of elements and molecular
compounds, to distinguish the molecular elements and molecular compounds are as
follows.
3.7 Moleculas unsure
Molecular elements are generally formed from non-metallic elements. Some non-
metallic element found naturally as molecules, atoms rather than as a stand-alone. One
example is oxygen. Oxygen gas contained in the air consists of molecules of O2. This
happens because the more stable form of oxygen molecules from the atoms as a stand-
alone. When heated at high temperatures, the molecules will break down into oxygen
atoms. Some examples of elements (non metallic) which exist as molecules are as
follows:
Elements that exist as molecules and molecular formula.
Nama Unsur
Lambang Unsur Rumus Molekul
Hidrogen H H2
Nitrogen N N2
Oksigen O O2
Fluorin F F2
Klorin Cl Cl2
Bromin Br Br2
Iodin I I2
Fosforus P P4
Belerang S S8
The formula states melekol arrangement of molecules, O2 stated that each
molecule consists of two atoms, P4 means that each molecule consists of four requi
3.8 Compound molecules
Molecules of compounds consisting of two or more kinds of atoms. Examples of
water molecules that have been mentioned in the previous section. Another example of
a molecule of ammonia (NH3) and methane molecule (CH4).
Various types of molecules we have seen in the discussion above. All the examples
given is a simple molecule, composed of two atua are three types of elements and
consists of only a few atoms only. Many also include a very complex molecule is a
molecule compounds found in living things, such as vitamin B2, Protein, and DNA.
Many of the molecules of compounds that play a role in living systems that are used to
address various health issues, including genetic engineering.
Quiz
. Below is a few pictures of molecules. for these molecules is by filling in the blanks
available with the molecule compound or molecular elements.
exercise
Choose one correct answer!
1. Substances that can not be described again into other substances by ordinary
chemical reaction called .......
a. element c. molecule
b. d. compoun d ion
2. Substances that are composed of multiple elements with a fixed ratio is
called .......
a. solution of c. compound
b.combine d. mixture element
3. The lightest element is .......
a. . hydrogen c. carbon
b.. oxygen d uranium
4. The most serious element is .......
a. uranium c. oxygen
b. hydrogen d. carbon
5. The symbol of the element zinc is .......
a. Al b.Cu. C. Zn D Fe
6. The person who first gave the letter symbols on each element is .......
a. John Dalton c. Thomson
b. Jons Jakob Berzelius d. Rutherford
7. Substances that may decompose through chemical reactions used to be the
substances that are more sedehana called .......
a. element c. atom
b. molecules d. compound
8. Below that is not an element molecule is .......
a.. N2 B. Br2 c. Cl 2 d. HNO
9. Known molecular formula of alcohol is C2H5OH, Means in 2 molecules of
alcohol are .......
a. 2 atom b. 8 atoms c. 9 atom d. 18 atom
10. Here is a molecule-molecule compounds, except .......
a. O2 b.H2SO4 C.NaNO3 d. HNO3
example
3.9 Empirical formula
Empirical formula shows us that there are elements and the simplest integer ratio
of the atoms, but do not always have to show the true value in a molecule. For
example, hydrogen peroxide has the molecular formula of H2O2. This formula
indicates that the ratio of hydrogen atoms with oxygen atoms in the molecule is 2:2 or
1:1, so the empirical formula HO.
An analysis of the ionic compound indicates that the compound contains 2.82 g of
sodium, 4.35 g of chlorine, 7.83 g of oxygen. Determine the empirical formula of the
compound
Solution
Determine the time of each element of Na Cl O
1.82 4.35 7.83
Numbers with each Ar2.8223
4.3535,5
7,4816
Comparative smallest 0.123 0,123 0,489
So the empirical formula 1 1 2
then in may NaClO2
RELATION BETWEEN ATOM, MOLECULES and IONS IN LIVE
A. The relationship between atoms, ions and molecules
In the foregoing discussion has known how the concept of atoms, ions and
molecules are all interconnected as one example in this case the production of
sugar. We imagine that one tablespoon of granulated sugar is composed of tiny
grains of sugar. If one spoon of sugar is dissolved in water it will dissolve the
sugar, the sugar particles dispersed into the water with a very small size so can
not be filtered even can not be seen by the eye. Though transformed into particles
whose size is very small nature of the sugar is not lost. Small particles of sugar
still has the same properties with granulated sugar molecule called glucose. The
smallest particle of matter can be shaped constituent atoms, ions and molecules.
So we can conclude that the atom is the smallest part of an element, and the
molecule is the smallest particle of a compound composed of two atoms or more.
Molecules composed of atoms called molecules of different compounds.
Molecules are composed of atoms called molecules of the same element. While
the ion is a collection of atoms that are electrically charged, positively charged
ions can (cations) and negatively charged (anions)
B. The material is composed of atoms, ions and molecules
Basically molekules theories of physics to explain the change, but not necessarily
able to explain the chemical changes, because it developed the atomic theory
which states that all matter consists of particles of very small particles called
atoms. In 1803, John Dalton a British propose a theory which states that matter
consists of atoms. Dalton's atomic theory can be summarized as follows:
1. Each is composed of the smallest particles of matter called atoms
2. Atom can not be broken down into smaller particles with similar properties
3. The atoms of certain elements have identical properties and mass. Different
elements have atoms of different mass.
4. Compounds are formed from two or more kinds of atoms are different.
5. Chemical reactions are merging and splitting the atoms of the element or
compound in the reaction.
So a material composed of several molecules, the molecules are composed of several
atoms of the same or different, for example: Oxygen (O2) is composed of two oxygen
atoms, water molecules (H2O) is composed of two hydrogen atoms and one oxygen
atom, molecule of sulfuric acid (H2SO4) is composed of two hydrogen atoms, one
sulfur atom and four oxygen atoms.
Likewise with other chemical products as an example: The production of urea
fertilizer with chemical composition NH2CONH2, NH4NO3, NH4 H2 PO3 dan KCl .
Aspirin C9 Ha O4 NH2CONH2, NPK fertilizer / fertilizer compound with the
composition of the mixture of NH4NO3, NH4 H2 PO3 and KCl. Acetic acid
CH3COOH is used as food vinegar. C11 22 O11 sucrose is used as a sweetener. Ha C9 O4
Aspirin is used to reduce pain.
Compounds of the formula is a combination of symbol element that shows the type of
compound-forming elements and the number of atoms of each element, such as
sucrose with the formula C12H22O11 formula shows that sucrose is composed of 12
carbon, 22 hydrogen and 11 oxygen
.
Table. Examples of that can be consumed by humans directly
exercise
Answer the question below correctly!
1. Name the following compound-forming elements and determine the amount
Of insur, the atoms in each molecule:
a. Baking soda ( Na HCO3)
a. Caffeine ( C8 H10 N4 O2)
b. Asam cuka ( C2 H2 O4)
2. Explain the relationship between atoms, ions and molecules.
3. Make a concept map classification of the material by completing the
following
MATERI
chart with the concepts that have been provided.
- Concepts: Homogeneous elements of compound. Heterogeneous mixture of
single substances
- Chart:
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