8.4 - Chemical Bonds & Equations

3. A mathematical model that displays the number of atoms of each element that form a chemical compound is called a chemical ___.
5. If the total energy required to break bonds in the reactants is ___ than the total energy released when the new bonds are formed in the products, the reaction is endothermic.
6. ___ ___ do not normally form bonds because they have a full set of valence electrons.
8. In a chemical ___, a substance is changed to a new substance with different properties.
9. If the total energy required to break bonds in the reactants is ___ than the total energy released when the new bonds are formed in the products, the reaction is exothermic.
11. In a chemical equation, the ___ are written on the right.
13. Nonmetals tend to gain electrons in chemical reactions, forming ___ ions.
15. In a chemical equation, the ___ are written on the left.
17. Metals tend to lose electrons in chemical reactions, forming ___ ions.
19. Compounds consist of two or more elements that are ___ combined in a fixed ratio.
20. In a chemical formula, the ___ tells you the number of molecules of the compound.
22. We use coefficients to ___ chemical equations because the mass of the reactants must equal the mass of the products.

1. In a chemical equation a(n) ___ indicates a change to new substances.
2. A chemical ___ describes a chemical reaction with symbols and formulas.
4. In ionic bonding, atoms ___ electrons.
5. The Law of Conservation of Matter states that regardless of how substances in a closed system are changed, the total ___ remains the same.
7. A burning match is an example of a(n) ___ reaction.
8. In an exothermic reaction, energy is ___.
10. Melting ice is an example of a(n) ___ process.
12. In ___ bonding, two nonmetals react.
14. In a chemical formula, a(n) ___ tells you the number of atoms of the element to the left.
16. In an endothermic reaction, energy is ___.
18. In covalent bonding, atoms ___ electrons.
21. In ___ bonding, a metal reacts with a nonmetal.