BIOLOGY NOTES BIOLOGY &
BIOCHEMISTRY PART 2PAGES 36-39
Standards___ Interpret formula representations of
molecules and compounds in terms of composition and structure
Essential Question1.
1.4
Why are carbon based molecules the foundation of life?
I. MatterMatter = anything that occupies _____ and
has _____.
List three different types of matter…
spacemass
A. The Structure of Matter
1. Atoms = the basic units of ________
• Atoms can be broken down into smaller parts called ____________ particles
a. proton = subatomic particle that has a ________ charge
matter
subatomic
positive
nucleus = the center of the ______ where protons and neutrons are located
c. electron = subatomic particle that has a ________ charge
electrons are in constant ________ around the _________ in an area known as the electron cloud
atom
negative
motionnucleus
b. neutron = subatomic article that has ____ charge
no
The electron cloud has different ________ levels that can hold a specific number of electrons
1st level (closest to the nucleus) =
______ electrons
2nd level = ______ electrons
2
8
energy
electron
neutron
proton
2. Elements
Element = a pure substance that consists
entirely of _______ type of atom
• elements cannot be _______ down into simpler substances
• each element is represented by a _______ symbol
1
broken
chemical
Oxygen = ___
Sodium = ___
Chlorine = ___
Sulfur = ___
Hydrogen = ___
Carbon = ___
Potassium = ___
Magnesium = ___
Calcium = ___
Phosphorus = ___
Nitrogen = ___
Iron = ___
ONa
ClS
H
C
K
Mg
CaP
N
Fe
• Of the naturally occurring elements, only about 25 are essential to ______.
• Of these 25, four ___, ___, ___, and ___ make up 96% of the mass of a human and are essential for life.
• The rest of the elements are present in very _______ amounts.
life
C H O N
small
1. Atomic Number = the number of _________ in an element.
• This is the element’s __________ because no two elements have the same amount of protons.
e.g.
protons
fingerprint
C = 6, N= 7, O = 8, etc.
II. The Combination of Matter
A. Compounds
Compound = a substance formed by the
________ combination of ___ or more
elements.
e.g.
chemical 2
NaCl (salt)H2O (water)C6H12O6 (glucose)
• chemical formula = a shorthand method of writing compositions of ___________
e.g. salt = NaCl water = H2O
• subscript = in chemical formulas, the small _______ next to the element that tells how many ______ of that element are in the compound
e.g. H2O = 1 atom O, 2 atoms H
C6H12O6 = 6 atoms C, 12 atoms H, 6 atoms O
numberatoms
compounds
How many atoms of each element are there in…..
C7O3H2 =
C57H110O6 =
7 atoms carbon, 3 atoms oxygen,2 atoms hydrogen
57 atoms carbon,110 atoms hydrogen,6 atoms oxygen
C7N4O2H9 =
CO2CaNa =
7 atoms carbon,4 atoms nitrogen,2 atoms oxygen,9 atoms hydrogen
1 atom carbon,2 atoms oxygen,1 atom calcium,1 atom sodium
B. Chemical Bonds – the formation of compounds
Elements will only combine to form
compounds when they become more
______ by forming a compound
• Atoms of different elements become more stable when they have ______ electrons in their outer ___________
stable
eightenergy level
(valence shell = outer energy level)
1. Types of Chemical Bonds
a. Ionic Bond = a chemical bond formed between two ______ when one or more _________ are transferred between the atoms resulting in atoms of _________ charge which are attracted to each other
e.g.
atomselectrons
opposite
salt
b. Covalent Bond = a chemical bond
formed between two _____ when they
share two or more _________
e.g.
atomselectrons
water, carbohydrates, & fats
• molecule = the structure that results when atoms are joined by _________ bonds
molecules make up most of the compounds found in ______ things
superscript = in chemical formulas, the large number found in ________ of compounds that tells how many ___________ of that compound exist
e.g.
covalent
living
front
molecules
2H20 = 2 molecules of water(4 atoms of Hydrogen, 2 atoms of Oxygen)
How many molecules? vs. How many atoms?
5C10O4H4 =
3C12H13ON =
5 molecules of polyestervs.
50 atoms carbon,20 atoms oxygen,
20 atoms hydrogen
3 molecules of bug sprayvs.
36 atoms of carbon39 atoms of hydrogen
3 atoms of oxygen3 atoms of nitrogen