Chemistry

3. A pure substance made of only one kind of atom.
4. A positively charged ion formed when an atom loses electrons.
5. A combination of two or more substances that are physically blended, not chemically bonded.
7. A negatively charged ion formed when an atom gains electrons.
9. I have 5 protons and 7 electrons. What is my charge?
10. The average mass of all isotopes of an element, weighted by their abundance.
12. Electrons in the outermost energy level that determine bonding behavior.
13. A change that produces one or more new substances with different properties.
14. The number of protons in an atom; identifies the element on the periodic table.

1. A reaction in which one element replaces another in a compound.
2. The ability to reproduce a measurement consistently under the same conditions.
4. A bond formed when atoms share electrons.
6. A property that depends on the amount of matter present, such as mass or volume.
8. Identify the type of reaction: 2 NaI + Pb(NO3)2 → 2 NaNO3 + PbI2.
11. The smallest unit of an element that retains its chemical properties.