Period Table Crossword Puzzle

5. Electron An electron in the outermost shell of an atom, which participates in chemical bonding.
6. An element that is typically shiny, ductile, malleable, and good conductor of heat and electricity.
7. Metal An element in Group 1 of the periodic table, highly reactive and readily lose one electron to form a positive ion.
8. An element that is usually brittle, poor conductor of heat and electricity, and often exists as a gas at room temperature.
10. A vertical column on the periodic table, containing elements with similar chemical properties due to the same number of valence electrons.
14. Atoms of the same element with a different number of neutrons, resulting in a different atomic mass.
15. Number The number of protons in the nucleus of an atom, which uniquely identifies an element.

1. Earth Metal An element in Group 2 of the periodic table, less reactive than alkali metals but still readily form positive ions.
2. An element in Group 17 of the periodic table, highly reactive nonmetals that readily gain one electron to form negative ions.
3. An element with properties intermediate between metals and nonmetals, sometimes exhibiting semiconductor behavior.
4. Configuration The arrangement of electrons in an atom's electron shells, which influences its chemical behavior.
9. A pure substance made up of only one type of atom, identified by its atomic number on the periodic table.
11. A horizontal row on the periodic table, representing elements with the same number of electron shells.
12. Gas An element in Group 18 of the periodic table, very unreactive due to a full valence electron shell.
13. Mass The average mass of all isotopes of an element, usually expressed in atomic mass units (amu).