Chapter 1 Vocabulary Pt. 1

4. — The total number of protons and neutrons in an atom.
5. — A substance made of two or more different elements chemically bonded together.
6. — Atoms of the same element that have different numbers of neutrons.
8. — A material that conducts electricity better than an insulator but not as well as a conductor.
10. — The small, dense center of an atom that contains protons and neutrons.
12. — A chart that organizes all known chemical elements by their properties and atomic number.
14. — A one- or two-letter abbreviation used to represent an element.
16. — A horizontal row on the periodic table.
18. — The smallest unit of an element that retains the properties of that element.
19. — How easily a substance reacts with other substances.

1. — An electron in the outermost energy level of an atom.
2. — The number of protons in the nucleus of an atom.
3. — The average mass of the atoms of an element.
7. — Able to be hammered or shaped into different forms without breaking.
9. — A vertical column on the periodic table.
11. — A negatively charged particle found outside the nucleus of an atom.
13. — A particle in the nucleus that has no electrical charge.
15. — The way a substance reflects light; often describes the shininess of metals.
16. — A positively charged particle found in the nucleus.
17. — Able to be stretched or drawn into a wire without breaking.