Unit 3.1 The Periodic Table & Periodic Trends

Periodic Table

A list of all known elements arranged in order of increasing atomic number.

Period

A row of elements in the periodic table.

Group

Elements aligned vertically in columns in the periodic table.

Valence Electrons

Electrons in the outer shell of an atom.

s-block

Elements with only s electrons in the outer shell.

p-block

Elements with at least 1 p-electron in the outer shell.

d-block

Elements with at least 1 d-electron and at least 1 s-electron but no f or p electrons in the outer shell.

f-block

Elements with at least 1 f-electron and at least 1 s-electron but no d or p electrons in the outer shell.

Atomic Radius

The size of an atom, the distance between the nucleus of an atom and the outermost electron shell.

Ionic Radius

The size of an ion.

First Ionization Energy

The amount of energy required to remove 1 mole of electrons from 1 mole of atoms to form 1 mole of gaseous ions.

Electron Affinity

The amount of energy released when 1 mole of electrons is gained by 1 mole of atoms to form 1 mole of gaseous ions.

Electronegativity

The ability of an atom to attract an electron pair in a covalent bond.

Metals

Elements with 1-3 valence electrons, metallic bonding, good electrical conductivity, basic oxides, and malleable physical characteristics.

Non-metals

Elements with 4-7 valence electrons, covalent bonding, poor electrical conductivity, acidic oxides, and flaky/brittle physical characteristics.