1. Periodicity
Trends and patterns

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

3. 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