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Homework - Unit 2

Assignment name Date due Points earned

Vocabulary for Unit 2

The Birth of a New Element

States of Matter

Chemical and Physical Changes

Bill Nye – Atoms

Atomic Structure

Atoms Family

Atomic Structure Internet Search

Chemistry Atomic Structure Practice

NOVA – Hunting the elements part 1

Drawing elements

Lewis dot structures

Valence Electrons and Ionic Charge

Atomic Structure - Ions

Summary:

Atomic Structure: Structure of the atom, symbols, what atoms look like, position of subatomic particles Be able to find protons, neutrons and electrons using the periodic table Know how the periodic table is organized (use the periodic tables you made)

Know the sections, groups, and families

Chemical and Physical changes Know the four signs of a chemical reaction Know examples of chemical and physical changes Know the changes of state (phase changes)

Atomic Diagrams:

Draw atoms showing electrons and energy levels Valence electrons and energy levels Lewis dot diagrams

Ions: Know how elements change when the become an ion Be able to calculate the number of each type of subatomic particle for a given ion Be able to predict the “Oxidation number” or charge of an element when it ionizes

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Uni

t 2

Atomic symbol

Atomic mass

Mass number

Proton

Neutron

Electron

Nucleus

Energy level

Phase Change

Chemical Change

Precipitate

Heterogeneous

Homogenous

Inert

Bohr Diagram

Lewis dot diagram

Valence electron

Ion

Cation

Anion

Oxidation Number

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The Birth of a New Element

By MICHAEL LEMONICK Monday, Oct. 16, 2006 Time Magazine – Science and Space What makes oxygen oxygen and not, say, iron is not what these two elements are made of—both kinds of atoms have nuclei made of protons and neutrons, with a surrounding cloud of electrons. It's how many of these basic building blocks their nuclei contain. The fact that an oxygen atom has 8 protons, in particular, and iron 26 largely explains why you can breathe one and make a frying pan from the other. But once you get to plutonium, with 94 protons, you've run out of naturally occurring elements. They may have once existed, but they're radioactive, and decay so quickly that there's none left on Earth, or, as far as we know, in space. Or there wasn't, rather, until physicists armed with cyclotrons began making them during World War II creating such exotic substances as Americium (95 protons), Curium (96), Berkelium (97). The more protons (and neutrons, which tend to add up even faster), the harder it is to make a new element—but that hasn't stopped scientists from trying. So it was with great fanfare Monday that experts at the Lawrence Livermore National Laboratory, in California, announced the newest element was created in a particle accelerator in Dubna, Russia, that shot a beam of calcium-48 ions (containing 20 protons) into a target of californium-249, an artificial element with 98 protons. To create a mere three atoms of element 118, the scientists spent two months smashing "bullets" of calcium at a target of Californium about 10,000,000,000,000,000,000 times. "Most of them just go right through the target and don't do anything," said Mark Stoyer, a nuclear chemist at Lawrence Livermore National Laboratory who was part of the research team. Only rare head-on collisions occurring with just the right energy caused the two elements to stick together to form a new super-heavy atom, Stoyer said. A detector allowed the researchers to track radiation and by-products created by the high-energy collisions. It isn't the first time scientists have announced the manufacture of element 118; in 1999, physicists at the rival Lawrence Berkeley Lab said they'd done it. But that claim was retracted amid allegations of fraud by one of the scientists involved. This time, the researchers were careful to double-check everything many times; the achievement still has to be duplicated at another lab to be considered rock-solid, but it appears to be a pretty good case. Unfortunately, the atoms lived less than a millisecond before decaying, first into element 116, then 114, then 112 and finally fragmenting completely. It wasn't unexpected, but atomic physicists believe, for theoretical reasons, that atoms with 120 or 126 protons might be a lot more stable. Of course, they were saying that about element 114 a few years ago, and it didn't pan out. But if they get to a point where one of these super-heavy elements lasts for hours, not milliseconds (it will depend in part on getting the right number of neutrons as well), that would be enough time to do actual chemistry and understand their properties. It could happen, say the researchers, within 5 to 10 years, if a dedicated accelerator could ever get funded. That's the goal of all this work — there's pretty much no conceivable practical application for any of this stuff. Until it's confirmed, element 118 remains nameless, although if you Latinize the numerals, it sounds sort of like a name. So for the foreseeable future, it will be known as "Ununoctium," at least to its friends.

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States of Matter – iPad

This assignment is based off the Study Package application on the science iPads. Begin by opening the “Study Package” located on the main screen and choose “Particle Theory” from the table of contents.

1. What are the three main states of matter?

2. Fill in the change of state (phase change) diagram with the correct terms and sketch what each phase looks like at the molecular level in the appropriate box (solid, liquid, gas):

3. Give an example of sublimation:

4. At what temperature (Celsius) does water boil?

a. Is this a change of state? If so what states (or phases) does it change between?

5. Describe what happens to the vibration of particles as the temperature heats up:

6. Give an example of something with a “high viscosity”

7. What is diffusion?

8. When particles are heated they have _____________ energy and vibrate ____________. This causes the solid to _______________.

9. What would happen if the ring were allowed to cool down? Explain.

10. Spend some time navigating the remaining portion of the app and list at least one fact from each section:

a. Properties of matter

b. Solutions and mixtures

c. Atoms and molecules

• What is a molecule?

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Chemical and Physical Changes

When you go home tonight be thinking about chemical and physical reactions or changes. Matter is constantly undergoing chemical and physical changes. Write down a minimum of three physical changes and three chemical changes that you experience today/tonight. Chemical changes / reactions

•

•

•

Physical changes / reactions

•

•

•

For each of the following, determine whether a chemical or physical change is taking place: 1) Water is boiled in preparation for making pasta

• Chemical or physical change? (circle one)

• Your reason:

2) Thousand Island dressing and mayonnaise are mixed to make “secret sauce” for hamburgers

• Chemical or physical change? (circle one)

• Your reason:

3) A hot dog is cooked

• Chemical or physical change? (circle one)

• Your reason:

4) Old ham goes bad in the refrigerator

• Chemical or physical change? (circle one)

• Your reason:

5) A rock star gets a tattoo on his forehead

• Chemical or physical change? (circle one)

• Your reason:

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BILL NYE VIEWING ASSIGNMENT - ATOMS

1) What are the basic building blocks of matter?

2) Cutting a piece of cheese in half? How is that important to understanding atoms?

3) Scale, using the buzzing ball (proper portion of science) what is scale of the atom? How far from the nucleus are the electrons?

4) What are atoms mostly made of?

5) What makes atoms of one element different from another?

6) What are molecules?

7) Warren Buck, what does he use to study atoms?

8) What is matter? (Nothing the matter?)

9) Give examples of energy?

10) What is organic chemistry (carbon is the key to life)

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Atomic Structure

Fill in the Blank Complete each statement using a term or terms form the list below. Write your answers in the spaces provided. Some answers may be used more than once

Outside Protons Nucleus

Neutrons Atoms Smaller

Same Negative

No

Cancel out Electrons Positive

1. All matter is made of tiny particles called ______________________.

2. The number of ______________________ determines what element it is.

3. Electrons are ______________________ than protons and neutrons.

4. The center part of an atom is called the _____________________.

5. Electrons are found ______________________ the nucleus.

6. The main parts of an atom are ______________________, ______________________, and

______________________.

7. An atom has the ______________________ number of protons and electrons.

8. Since protons have a ______________________ charge, and neutrons have

______________________ charge, the nucleus will have a ______________________ charge.

9. A nucleus is made up of ______________________ and ______________________.

10. Electrons have a ______________________ charge.

11. The plus and minus charges of an atom ______________________ each other.

True or False _______ 12. A proton is found outside the nucleus.

_______ 13. An electron has a negative charge.

_______ 14. A neutron has a positive charge.

_______ 15. A proton has a negative charge.

_______ 16. An electron is found inside the nucleus.

_______ 17. The mass of atoms is measured in atomic mass units (amu)

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18) Fill in the following table about protons, neutrons, and electrons with information from your notes.

Name of particle Location Mass (in amu’s) Charge

19) Protons ___________

Neutrons __________

Electrons __________

Positive charge ________

Negative charge ________

Overall charge _________

What element is this?

20) Protons ___________

Neutrons __________

Electrons __________

Positive charge ________

Negative charge ________

Overall charge _________

What element is this?

21)

Protons ___________

Neutrons __________

Electrons __________

Positive charge ________

Negative charge ________

Overall charge _________

What element is this?

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The Atoms Family

The atomic number equals the number of ________________

The atomic weight rounded to a whole number is the: _______________

The mass number equals the number of _______________ + ______________

The number of neutrons equals the _______________ - ______________

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Atomic Structure Internet Search For the scientists listed below find out what they discovered (each of them discovered one of the four particles listed on the bottom of the page), the apparatus/tools they used to make the discovery and what their research suggested what the atom looked like. List the dates of the discovery JJ (Joseph John) Thomson Sketch of Model: James Chadwick

Ernest Rutherford List the charge and the mass of each subatomic particle. Find a diagram that is the modern accepted model of an atom; the electron cloud model. Make sure to put the subatomic particles into the correct position. Protons Modern Accepted Model: Neutrons Electrons Nucleus (not really a subatomic particle, do not list mass/charge)

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ATOMIC STRUCTURE PRACTICE SHEET

symbol protons electron neutrons atomic number mass number

B

5

Al

13

Au

40

27

11 12

15 16

53 127

Ga

31

Cu

29 29

35 80

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NOVA Video Questions: Hunting the Elements 1) Where does an element take its identity from? (5:30) 2) How much gold (Au) is extracted per ton of rock ore? (8:30) 3) How much does a gold (Au) bar weigh and how much is it worth? (13:00) 4) Why is copper (Cu) so widely sought on the world market and New York Mercantile Exchange? (16:00) 5) What is copper (Cu) combined with to make bronze? (18:00) 6) What makes metals like Copper (Cu) conductive to electricity? (20:00) 7) Bronze is an alloy. What is an alloy and why are they preferable at times? (22:00) 8) How does the atomic arrangement of atoms lead to its crystal structure like was seen in the sample of bronze with gold (Au) and tin (Sn) atoms? (32:00) 9) What is the atomic number and what does the atomic number indicate? (34:00) 10) Most of the periodic table is made of what type of elements? (35:00) 11) How did early chemists like Mendeleev classify the elements? (38:00) 12) How is the periodic table structured with regard to elements with similar properties? (40:00) 13) What makes noble gases stable? (43:00) 14) Why is an alkali metal element like Sodium (Na) so reactive? (45:00)

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He

Ne

Ar

Gro

up/F

amily

#

of v

alen

ce

elec

trons

Dra

w th

e fir

st 2

0 el

emen

ts (w

ith p

roto

ns, n

eutro

ns, a

nd e

lect

rons

in th

eir c

orre

ct lo

catio

ns)

The

Perio

dic

Tabl

e of

the

Elem

ents

(The

firs

t 20)

F Cl

Gro

up/F

amily

#

of v

alen

ce

elec

trons

O

S Gro

up/F

amily

#

of v

alen

ce

elec

trons

N

P Gro

up/F

amily

#

of v

alen

ce

elec

trons

C

Si

Gro

up/F

amily

#

of v

alen

ce

elec

trons

B

Al

Gro

up/F

amily

#

of v

alen

ce

elec

trons

Be

Mg

Ca

Gro

up/F

amily

#

of v

alen

ce

elec

trons

H

Li

Na

K

Gro

up/F

amily

#

of v

alen

ce

elec

trons

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Lewis Dot Diagrams

Lewis dot diagrams are a simplified way to show how the electrons are arranged in their outer shell. This is where the chemical reactions take place. Only valence electrons participate in chemical bonding.

1. What does each dot on a dot diagram represent?

2. In what order are the dot placed around the symbol for the element?

3. Where/how can you figure out the number of valence electrons an element has?

4. What is the most dots you will ever have on a dot diagram? Draw the Dot diagrams for the first 18 elements:

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Valence Electrons and Ionic Charges

Use the information on your periodic tables to complete the following modified periodic table. Each column represents a family/group.

# of

Val

ence

e-

ioni

c ch

arge

Alk

ali M

etal

s

Nob

le G

ases

# of

Val

ence

e-

ioni

c ch

arge

Alk

alin

e E

arth

Met

als

Bor

on G

roup

Car

bon

Gro

up

Nitr

ogen

Gro

up

Oxy

gen

Fam

ily

Hal

ogen

s

Elements have variable ionic charges

Transition metals

Elements have variable # of valence electrons

Circle one of the underlined terms to make the statement true.

1. The number of protons / electrons changes when an element forms an ion.

2. All metals will give up / take electrons.

3. If an element gains electrons to achieve a full outer shell then it will have a positive / negative overall

charge.

4. An element has a charge of +2. It gave up / gained electrons.

5. Non-metals give up / take electrons to form a full outer shell and therefore have a positive / negative

ionic charge.

6. In aluminum chloride, where aluminum and chlorine are bonded together the aluminum / chlorine will

give up electrons.

Short answer

7. Why do elements either gain or lose electrons to form ions?

8. Why does an element have a positive charge if it gives up 2 electrons?

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Atomic Structure – Ions An atom is made up of protons and neutrons (both found in the nucleus) and electrons (in the surrounding electron cloud). The atomic number is equal to the number of protons. The mass number is equal to the number of protons plus neutrons. In a neutral atom, the number of protons equals the number of electrons. The charge on an ion indicates an imbalance between protons and electrons. Too many electrons produces a negative charge, too few, a positive charge.

1. What is an ion?

2. The number of what subatomic particles change when an ion if formed?

3. What does a charge on an ion indicate about the number of protons and electrons?

4. What is the difference between atomic mass and mass number?

Element/Ion Atom or Ion?

Atomic Number

Mass Number Protons Neutrons Electrons

H

H+

N

Na+

F-1

Mg

Ca2+

P3-

Au

Au+1

O-2

I