Conservation of Mass

1. A substance made of two or more elements that are chemically combined.
4. The small number written after an element’s symbol that shows how many atoms of that element are in a molecule.
6. The amount of matter in a substance, usually measured in grams (g).
9. A chemical reaction in plants that uses sunlight to turn carbon dioxide and water into glucose and oxygen.
10. A shorthand way to show what happens in a chemical reaction using symbols and formulas.
14. The large number in front of a chemical formula that shows how many molecules are involved.
15. A one- or two-letter abbreviation for an element.
16. - An equation where the number of each type of atom on both sides is the same, showing mass is conserved.

1. Matter cannot be created or destroyed in a chemical reaction — it only changes form.
2. During a reaction, bonds break and new bonds form, but the atoms themselves are not created or destroyed — only rearranged.
3. A process in which atoms are rearranged to form one or more new substances.
5. A chart that organizes all known elements by their atomic number, symbol, and properties.
7. The starting substances in a chemical reaction — found on the left side of a chemical equation.
8. The new substances formed — found on the right side of a chemical equation.
11. Number The number of protons in an atom’s nucleus.
12. The smallest unit of matter that still has the properties of an element.
13. Two or more atoms bonded together.
17. A pure substance made of only one kind of atom.