1. Just a few elements, (usually bonded with other elements in compounds), make up most the matter on Earth.

2. 75 % of Earth is covered by…. saltwater. Saltwater is a mixture of two compounds. Water = H 2 O Salt = NaCl Based on this…what are the two most common elements in our oceans?

3. Decode the compound formulas – Water – H 2 O H = Hydrogen O = Oxygen Salt – NaCl Na = Sodium Cl = Chlorine

4. Percentage of Elements in the Hydrosphere / Oceans Element% Oxygen (O) 85.84 Hydrogen (H) 10.82 Chlorine (Cl) 1.94 Sodium (Na) 1.08 Magnesium (Mg).13

5. This graph shows the composition of our… Atmosphere

6. Is Oxygen (O) the most important element in our atmosphere? Is Oxygen (O) the most abundant element in our atmosphere? Only if you like breathing. NO! N – (N) Nitrogen = 78% O – (O) Oxygen = 21% About 1 % of the atmosphere includes traces of other element and… two important compounds. CO 2 Carbon Dioxide…plants need this. H 2 O Water Vapor (gas)…amount is variable.

8. The Earth’s Lithosphere /crust is dominated by 5 compounds. Compound% mass Silicon dioxide SiO 2 43% Magnesium oxide MgO 35% Ferrous oxide FeO 9% Aluminum oxide Al 2 O 3 7% Calcium oxide CaO 4% What do they all have in common? Oxygen (O)

9. Crust Elements % by mass Oxygen (O) 47% Silicon (Si) 28% Aluminum (Al) 8% Iron (Fe) 5% Calcium (Ca) 4% Compound% mass Silicon dioxide SiO 2 42% Magnesium oxide Mg O35% Ferrous oxide FeO9% Aluminum oxide Al 2 O 3 7% Calcium oxide CaO4% These are the elements found in the abiotic (non living) parts of Earth’s Lithosphere / Crust.

10. Common Elements for Biotic Matter Bio = life In the BIOSHPHERE Life ? Life = Grow Reproduce Respond Use Energy

11. C Carbon H Hydrogen N Nitrogen O Oxygen Four elements are always found in living systems.

12. C 6 H 12 O 6 sugar / carbohydrate CO 2 H2OH2O NN This is the chemistry of PHOTOSYNTHESIS !

13. C Carbon H Hydrogen N Nitrogen O Oxygen Remember “CHNOPS” (“ sha nops” ) “ORGANIC COMPOUNDS” are bonded with the following elements P Phosphorus S Sulfur