Periodicity Trends and patterns

Periodicity Periodicity is a regular periodic variation of properties if elements with atomic number and position in the periodic table.

Periodic properties Down groups elements become more metallic i.e. group IV (C – Pb) Across periods elements become less metallic i.e. period 2 (Li – Ne) Electronegativity increases from left to right of the periodic table First ionisation energy generally increases across the periodic table Atomic radii decreases across the periodic table Atomic radii increases down groups Electronegativity decreases down groups Number of shells increases down groups First ionisation energy generally decreases down groups