1. 12.1 – NOTES Energy:Past and Present

2. Petroleum is nonrenewable
People need alternative forms of energy

3. D.1 Energy: Past and Present
Sun is the planet’s primary energy source
Radiant energy – energy from sun (solar energy) is stored in plants through photosynthesis
Plants convert CO2 and H2O into Carbohydrates and O2 gas
This type of energy is chemical potential energy
Energy is released and used by animals

4. Organic molecules found in plants/animals
Biomolecules
Organic molecules found in plants/animals
The digestion of plants is overall exothermic
More energy is released by forming products than breaking them down

5. Solar energy and energy in biomolecules are key energy sources for life on earth
Up till 1850
Natural energy sources, such as biomass, were used including wood, water, wind, and animal power
Reasons for needing other fuel sources included:
Industrialization
Population Increase