Chemistry

1. a chemical reaction in which a substance loses electrons.
4. means more molecules in a given space, increasing the chance of collisions and speeding up reactions.
6. reactions are common endothermic reactions.
7. a chemical reaction in which a substance gains electrons.
8. the process when energy is released to the surroundings
10. is one or more forms of a chemical element that can exist in the same physical state.
11. speed up reactions without getting used up themselves.
12. reaction is a chemical reaction in which the product can react to produce the original reactant. It can move in both forward and backward directions.

2. the approximate percentage of argon in air
3. means using electricity to coat one metal with another.
5. generates electrons in the reaction and is oxidized. It reduces another substance by generating electrons.
9. a chemical reaction that uses nitrogen gas and hydrogen gas to create the chemical compound ammonia.