1. ELEMENTS There are 92 elements found naturally
The most common elements in living things are:
Hydrogen (H) 59% Oxygen (O) 24% Carbon (C) 11% Nitrogen (N) 4% Others such as phosphorus (P) and sulphur (S) 2% combined

2. Law of Conversation of Matter
Matter can not be created nor destroyed it is just converted to a different form.
C6H12O6 – 24 total atoms
6 carbon atoms
12 hydrogen atoms
6 oxygen atoms

3. Photosynthesis 6CO2 + 6H2O + Energy C6H12O6 + 6O2
How many total atoms are there? _________
How many are there are each side?
Balance the equation
C = C =
O = O =
H = H =
© 2004 Delmar Learning, a Division of Thomson Learning, Inc.

4. Compounds or Inorganic Compounds Organic Compounds
usually don’t contain Carbon
generally come from the earth
generally simple molecules
Usually ionic bonding
always contain C & H and usually O, N, sometimes S & P
originate in organisms
generally complex molecules
Usually covalent bonding

5. Examples of Inorganic Compounds
H + O
= H2O = Water
H + Cl
= HCl = Hydrochloric Acid
C + O
= CO2 = Carbon Dioxide
Na + Cl
= NaCl = Common Table Salt

6. What are the 6 most common elements found in all living things.
a. Carbon, Helium, Nitrogen, Oxygen, Potassium and Sodium b. Carbon, Hydrogen, Nitrogen, Oxygen, Potassium and Sodium c. Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus and Sulfur d. Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus and Sodium

7. Examples of Organic Compounds
C, H + O
Carbohydrates = Sugars, starches & cellulose
C, H + O
Lipids = Fats & Oils
C, H, O, N, & sometimes P + S
Proteins
C, H, O, N, + P
Nucleic Acids – DNA & RNA

8. Find and circle the 6 most common elements found in living things