COMPETENCY 2
Name ______________________________
CHEMISTRY OF LIFE
________________: smallest unit of matter.
 Subatomic particles
1. ________________________
a. Inside nucleus
b. Neutral charge
2. ________________________
a. Inside nucleus
b. Positive charge
3. _________________________
a. Outside nucleus
b. Move at speed of light
c. Have a negative charge
Atomic number and Weight:
 _________________________________: number
of protons in the nucleus.
 _________________________________: number
of protons plus neutrons in the
nucleus of the atom (a.k.a. mass
number)
How many neutrons are in an atom?
Subtract the number of __________________from the mass number to get the number
____________________________.
__________________________________ - Atomic number = # of neutrons.
Finding the number of protons, neutrons, electrons, atomic number and mass number
Atomic
Mass
# of
# of
# of
number
number
protons
electrons
neutrons
Carbon
Hydrogen
Oxygen
Electron Shells
1. Energy Shells
a. First level can only have _________ electrons.
b. Second level can have __________ electrons.
c. All other levels have ____________.
2. The chemical behavior of the atoms is determined by the atom’s
_______________________ ______________.
3. ____________________________ _____________________________ - outermost shell.
Chemical Bonds
1. Making of chemical bonds __________________________________________________.
2. The breaking of chemical bonds ___________________________________________.
Covalent bonds:
 The _______________________of a pair of valence electrons by two atoms.
 Between two ________________________________.
 Can form a single, double, and triple bonds.
 All non-metals form _______________________________________. Examples are: glucose, water, carbon
dioxide, sucrose.
Ionic Bonds
 One atom ____________________ electrons from another to complete its outer shell.
 Between a ___________________________ and ____________________________________.
 Example: __________________
In Polar Covalent Bonds
 Electrons are sharing ________________________ between atoms creating a polar molecule.
Strength of Bonds
__________________________ > _______________________________> ________________________________
Water is a major competent of cells
 ___________ of all molecules in the body (all your cells are surrounded by water)
 _______________________ stores heat efficiently.
a. _______________________ helps release heat.
b. helps maintain ________________________________ by regulating temperature.
Properties of Water
 Water is the _________________________ of life (_____________________________________)
 Polar solutes dissolve when ____________ molecules surround them forming _____________________
solutions.
 Water is _____________ ________________ as a _______________ than liquid. Ice floats on water. Ex:
Cohesion and Adhesion
 Hydrogen bonds make water _________________________________ (water sticks to ________________)
ex: Insects can walk on water due to _________________________ _____________________________ which
is the cohesion of water molecules at the ___________________ of a body of water.
 Water is ___________________________(water sticks to _________________________________) ex: molecules
can move from a plant’s roots to its leaves (____________________________
_____________________________); water moves up a straw.
Water dissolves many substances.
 Water is the ________________________________. What is being dissolved is the ____________________.
 ____________________________: mixture in which one or more substances is evenly distributed.
Solute and Solvent together make a solution.
 ____________________________: molecules with an electrical charge.
Polarity
 Water is a _____________________ molecule.
 Only polar molecules will dissolve in water.
 ___________________________ molecules will not dissolve in water. Ex: oil

_________________________________ bond occurs when an atom of hydrogen has a strong attraction
to ___________atoms instead of one.
 The atoms must be highly electronegative (electron loving) like Oxygen, Fluorine, Nitrogen,
Chlorine, and Bromine.
Specific Heat
 Water has a ______________ __________________________________.
 Specific heat is the amount of energy required to change the _____________________________of
substance. It allows for moderate of climate and helps organisms regulate body temperature.
 Water has a high __________________ of ____________________________ (the amount of heat required to
convert liquid water into gaseous water) aka steam. This makes an effective coolant for
That’s why sweating actually cools us down. (____________________________ _______________________)
 Water has a high boiling point (100 degrees Celsius) and low freezing point (0 degrees
Celsius)
 Water has a ________________ pH. Which makes a good buffer. A ______________is a substance that
helps to moderate any changes in pH that result from the addition of acids or bases.
pH Scale
 pH Scale: based on concentration of ____________ (1-14)
 pH of ______________ < 7 (
)
 pH of _______________> 7 (
)
 pH of neutral = 7
 If ________________ pH is either below 6.9 or above 7.8 a person cannot survive.
 Water can be broken down into acids and bases.
 ACIDS: high concentration of ____________________________ ions (H+) ; low
_______________________________ (OH-) and has a pH less than ________ ex: HCL
 BASES: high concentration of _____________________________ ions (OH-); high concentration of
__________________________ ions (H+) and has a pH greater than _________. Also called alkaline.
Examples of Acids: _______________________________________________________________________________________
Examples of Bases: ______________________________________________________________________________________