CHEMISTRY OF LIFE1. Matter:

a. All matter takes up space and has mass

b. All living and nonliving matter are made up of elements

c. Elements are pure and are naturally occurring

* elements cannot be broken down into substances with

different chemical or physical properties.

2. Six elements make up 98% of all living things

C= Carbon, H=Hydrogen, N=Nitrogen, O=Oxygen

P=Phosphorus, S=Sulfur

3. Compounds: 2 elements bonded together.

CHEMISTRY OF LIFE CON’T

Elements: Pure substance, only 1 kind of atom. Represented by a letter: O , N, P Or two letters: Mg, Cu, Li

Compound: Two elements bonded together.

Ex: NaCl, H2O

Molecular Formula: Tells you how many atoms of each element in a molecule.

Structural Formula: graphical representation of the molecular structure, showing how the atoms are arranged

CHEMISTRY OF LIFE Atoms: smallest unit of matter that cannot

be broken down any further. a. Electrons: negative charge (e-) Outside

b. Protons: Positive charge (p+)

c. Neutrons: no charge (n) Inside the Nucleus

Atomic Number=Number of protons

Number of Protons=Number of Electrons

WHY BOND TOGETHER? 1. Arrangement of Electrons! Grouped into different levels Inner levels have more energy than outer levels. Outer levels must have a certain number of electrons in

it. If not, it is considered unstable and will react with other elements to help it have 8 in its outer shell becoming stable. (You will learn in chem that there are some levels that can hold more than 8. But for our purposes we are going to keep it at 8)

E1= 2

E2= 8

E3 = 8

ELECTRON DOT EXAMPLE

Cl

# of Protons= Atomic Number = 17

# of protons = # of electrons = 17

# neutrons = Atomic number – Atomic Mass

17 - 35.453 = 18

TYPES OF BONDS Covalent: When two or more atoms are shared between

elements.

Example H2O

IONIC BONDING

Ionic: When elements gain or lose electrons: creates a charge

a. If lose an electron: positive charge

b. If gain an electron: negatively charged

c. This charge difference is what attacks the two elements

HYDROGEN BONDING

Attraction between a partial positive and partial negative charge molecule. Partial negative charge is oxygen, fluorine, or nitrogen and partial positive charge is hydrogen

Special bonding between water

Link to animation of Hydrogen Bonding in Water - Northland Community and Technical College http://www.north

land.cc.mn.us/biology/Biology1111/animations/hydrogenbonds.html Weaker than covalent and ionic bonds Nonpolar: equal charge: do not like water Polar: Unequal charge: water liking

WATER Makes up nearly 70% of your body Helps move nutrients and other substances into and out

of your cells. Stores heat efficiently: water helps us maintain

homeostasis: Ex: humans sweat: water vapor lost through

evaporation carries heat,

cools body down.

Temperature falls more slowly protecting

organisms from rapid temp. changes Hydrogen bonds between water molecules require a large

amount of heat to break

Bonding

1. Cohesion: Attraction between same type of substances:

a. surface tension: water can stretch without breaking easily

2. Adhesion: Attraction between different types of molecules

a. Capillary Action: attraction of water to walls of tube sucks the water

more strongly than gravity pulls it down. Water moving through stems.

http://www.youtube.com/watch?v=CT4pURpXkbY

Cohesion of Water

Adhesion of Water

NON-POLAR VS POLAR Polar: water loving:

1. Substance attracted to water and will dissolve in water.

Non-Polar: Water hating1. Substances not attracted to water and will not mix with it.

ex: Oil: Non-polar molecules are pushed together forming beads or clumps in the

water.

pH LEVELS: ACIDS AND BASES Measures the amount of Hydrogen ions in a solution. When the bonds in water break apart to a Hydrogen ion

H+ and a hydroxide ion OH-

H2O H+ + OH- Scale: 0-6 Acid, 7 neutral, 8-14 Base Acids : Increased Hydrogen ions H+ Bases: Decreased Hydrogen ions OH-

(adding the oxygen decreases number of

hydrogen ions. )

MIXTURES: 2 OR MORE SUBSTANCES ARE BLENDED TOGETHER BUT ARE NOT CHANGED CHEMICALLY.

1. Solutions

a. One substance is completely dissolved into another substance

b. Solute: Substance being dissolved

c. Solvent: Substance dissolving the solute

ex: Salt water

https://www.youtube.com/watch?v=EBfGcTAJF4o&feature=related

2. Suspensions:

a. Particles spread through a liquid or gas, but settle out over time

ex: sandy water

3. Colloids:

a. Particles do not settle out, but stay suspended

ex: Jello