Periodic Trends

Ionization energy

-the energy required to remove an electron from a specific atom

-increases across a period

-decreases down a group

Shielding Affect

-the outer electrons being partially shielded from the attractive force of the protons in the nucleus by inner electrons

Electron affinity

-the energy change that occurs when a neutral atom gains an electron

-increases across a period

-decreases down a group

Ionic radius

-measure of the size of an ion, defines as half the distance b/w 2 identical ions that are just touching in a crystal lattice

-increases down a group

-decreases across a period

Electronegativity

-measures the ability of an atom to attract electrons

-increases across a period

-decreases down a group

Metallic

-refers to level of reactivity of a metal

-increases down groups

-decreases across periods

Nonmetallic

-refers to the level of reactivity of nonmetals

-increases across periods

-decreases down groups

Nuclear charge

-electrons gradually feel a greater attraction to the nucleus as the number of protons increases in an atom

-total charge of the nucleus, which affects the atomic size and ionization energy.

Effective Nuclear Charge

-net positive charge experienced by an electron in an atom

Atomic Radius

-explains why some molecules fit together & why other molecules have parts that get too crowded under certain conditions 

-decreases across a period

-decreases down a group