During the ____________________, About 2

Q62: _ reacts in moist air to produce

Q63: Little radiation is absorbed in the _

Q64: The most abundant constituent of our atmosphere

Q65: When coal burns, some minerals escape from

Q66: What was James Lovelock's hypothesis?

Q68: Without an atmosphere, describe what the Earth

Q69: When did cyanobacteria first begin producing oxygen?

Q70: The layer of air closest to Earth,

Q71: How much is a bar and a

Q72: What happens during photosynthesis?