This drawing represents a comet bringing atmospheric molecules and possibly primitive life forms to the Earth's surface.
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Like an acid
, a base
is a substance capable of dissolving things.
There are many bases. Here are a few: Ammonia (used as a cleaner), Calcium hydroxide (used in mortar for construction), Magnesium hydroxide (otherwise known as milk of magnesia; used as a laxative or antacid), Sodium hydroxide (used as an oven cleaner).
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Nitric acid is a very strong kind of acid. If you got some on your skin, it would burn you! Nitric acid has nitrogen, oxygen, and hydrogen atoms in it. Earth's atmosphere has a very, very tiny bit of nitric...more
Sulfuric acid is a very common type of acid. Acid rain has sulfuric acid in it. Acid rain harms plants, fish, and other living things. A type of air pollution causes acid rain. When people burn fossil...more
Methane is a kind of gas. There is a small amount of methane in the air you breathe. A methane molecule has carbon and hydrogen atoms in it. Methane is a greenhouse gas. That means it helps make Earth...more
Ammonia is a kind of gas. Ammonia molecules (NH3) have hydrogen and nitrogen atoms in them. The air you breathe has a tiny bit of ammonia in it. When plants and animals die and decay, they give off ammonia....more
There is more nitrogen gas in the air than any other kind of gas. About four out of five of the molecules in Earth's atmosphere is nitrogen gas! A molecule of nitrogen gas is made up of two nitrogen atoms....more
Oxygen (O2) is a kind of gas. A lot of the air you breathe is oxygen. That's a good thing, since we need oxygen to stay alive! About 4/5ths of the air in Earth's atmosphere is nitrogen (N2). Almost all...more
Hydrogen peroxide (H2O2) is a kind of chemical. A molecule of hydrogen peroxide has oxygen and hydrogen atoms in it. Hydrogen peroxide is a clear liquid. Hydrogen peroxide is in some liquids that are used...more