Chemistry Vocabulary

3. Organized chart of all known elements.
7. The dense center of an atom that contains protons and neutrons.
9. A vertical column on the periodic table with similar properties.
10. Positively charged particle found in the nucleus.
13. One or two-letter abbreviation that represents an element.
14. Number of protons in the nucleus; identifies the element.
16. Electron in the outermost energy level of an atom.
18. Atom or group of atoms that has gained or lost electrons.
20. Element with properties of both metals and nonmetals.
21. Negatively charged ion.
23. Positively charged ion.
26. A substance made of two or more elements chemically bonded in fixed ratios.

1. Elements in Group 2, somewhat less reactive metals like magnesium.
2. A horizontal row on the periodic table.
4. Reactive nonmetals in Group 17 that form salts with metals.
5. Compound formed by the attraction between positive and negative ions.
6. Sum of the protons and neutrons in the nucleus.
8. Elements in Group 18 that are stable and nonreactive.
11. Element that is typically shiny, malleable, and conducts electricity.
12. Elements in Group 1, highly reactive metals like sodium or potassium.
15. Substances formed when two or more elements bond chemically.
17. Element that lacks metallic properties; poor conductor of heat and electricity.
19. Negatively charged particle found outside the nucleus of an atom.
22. Neutral particle found in the nucleus.
24. Atoms of the same element with different numbers of neutrons.
25. The smallest particle of an element that retains its identity in a chemical reaction.