Periodic Trends

3. The likelihood of an element to undergo chemical reactions and form compounds with other elements.
8. A horizontal row on the periodic table, indicating the number of energy levels an element's atoms have.
9. A measure of how closely an element's properties resemble those of a metal, such as luster, conductivity, and malleability.
10. The size of an atom, typically measured as the distance from the nucleus to the outermost electron cloud.
11. A group of highly reactive nonmetals in Group 17 of the periodic table.
12. Systematic variations in properties of elements across a period or down a group on the periodic table.
13. The reduction in the effective nuclear charge on the outermost electrons due to the presence of inner electron shells.
15. The energy required to remove an electron from an atom, indicating an atom's tendency to lose electrons.
17. A pattern or tendency in the properties of elements across the periodic table.
19. A vertical column on the periodic table, also called a family, indicating the number of valence electrons and similar chemical properties.
20. The number of protons in the nucleus of an atom, which defines an element's identity on the periodic table.
21. element with properties intermediate between metals and nonmetals.
22. The positive charge in the nucleus of an atom, which attracts electrons.

1. that have properties of both metals and nonmetals, found along the "staircase" on the periodic table.
2. A group of elements that are chemically inert, stable, and typically found as gases.
4. Electrons in the outermost energy level of an atom that are involved in chemical bonding.
5. The ability of an atom to attract electrons when forming chemical bonds, indicating its tendency to gain electrons.
6. on the right side of the periodic table that are typically poor conductors of heat and electricity.
7. A group of metals in Group 2 of the periodic table, which are less reactive than alkali metals.
14. The principle that states that the physical and chemical properties of elements are periodic functions of their atomic numbers.
16. The energy change associated with adding an electron to an atom, indicating the atom's tendency to gain electrons.
18. A highly reactive group of metals in Group 1 of the periodic table.