Q: Fact 1: All chemical reactions require activation energy to get started. Fact 2: Chemical changes are referred to as a chemical reaction. Given the two facts above, what require activation energy to get started? | OPTIONS:
- changing colors
- chemical additions
- reacting colors
- Firecrackers
- an engine
- heating liquids
- Organic compounds
- chemical changes
A: chemical changes

Q: Fact 1: Fog is formed by water vapor condensing in the air. Fact 2: When air cools, the water vapor in the air condenses.". Given the two facts above, fog is formed when? | OPTIONS:
- summer end
- evaporation
- Winter
- movement
- air cools
- Wet weather
- rainy
- dry and hot
A: air cools

Q: Fact 1: Soil is formed by weathering. Fact 2: Soils are formed by breakdown of rock. Given the two facts above, _ is the breakdown of rock.? | OPTIONS:
- Weathering
- mechanical
- salinity
- heat energy
- dangerous
- cycles
- calcite
- started
A: Weathering

Q: Fact 1: Most carcinogens cause cancer by producing mutations in DNA. Fact 2: If it causes changes in DNA, it is considered a mutagen, or potential carcinogen. Given the two facts above, what cause mutations in DNA? | OPTIONS:
- Pesticides
- smoking
- chromosomes
- protein
- cigarettes
- mutagens
- amino acids
- animals
A: mutagens