Chemical reaction

3. is a chemical equation with the same number of atoms of each element on both sides of the arrow
4. A chemical reaction that releases energy in the form of light or heat
9. Gain of electrons
11. is the number in front of the formula, that is related to the properties of the products. For example 2 H2O means there is two molecules of water
12. A type of lettering form written lower than the things around it. In chemical formulas the number of atoms in a molecule is written in this manner
13. The speed at which reactants are converted in products
14. A representation of a chemical reaction using symbols of the elements to indicate the amount of substance, usually in moles, of each reactant and product.
16. Are those which absorb energy from the surroundings and result in a net decrease in temperature

1. for any system closed to all transfers of matter and energy, the mass of the system must remain constant over time, as the system's mass cannot change, so quantity cannot be added or removed.
2. A substance that takes part in and undergoes change during a reaction
5. The amount of a substance that contains 6.02 x 1023 particles of that substance
6. A substance that slows down or prevents a particular chemical reaction or other process, or that reduces the activity of a particular reactant, catalyst, or enzyme.
7. Is a substance that is formed as the result of a chemical reaction.
8. A substance produced by a living organism that acts as a catalyst to bring about a specific biochemical reaction
10. Loss of Electrons
14. eaction:A process in which one or more substances, the reactants, are converted to one or more different substances called the products
15. Mass in grams of one mole of a substance
17. A substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change.