Trends of the Periodic Table

electronegativity

the ability of an atom to attract an electron

atomic radius

distance from the nucleus to the valence shell

ionisation energy

energy required to remove an electron

metallic character

tendency of atoms to lose an electron

core charge

net charge of a nucleus

calculating core charge

protons minus inner electrons

mass number

the number of protons and neutrons in the nucleus of an atom

electron shell

regions surrounding the atomic nucleus

valence shell

the outermost electron shell

isotopes

An atom with the same number of protons and electrons but different number of electrons

ground state

an atom in which all electrons occupy the lowest possible energy level

excited state

an atom in which electrons occupy higher energy levels by absorbing energy and jumping to a higher energy level

atomic radius across a period

decreases

atomic radius down a group

increases

electronegativity across a period

increases

electronegativity down a group

decreases

first ionisation energy across a period

increases

first ionization energy down a group

decreases

metallic character across a period

decreases

metallic character down a group

increases

blocks

s, d, p, f

group 1 elements

alkali metals

group 2 elements

alkaline metals

group 3-12

transition metals

group 17

halogens

group 18

noble gases