Periodicity (AS)

• Periodicity is the term used to describe the repeating patterns seen within groups and periods.
• Across period 3 the nuclear pull increases and the electrons are attracted to the nucleus.
• Electronegativity increases as you go across a period because the nucleus has a stronger force of attraction between the outer shell electrons.
• The modern periodic table arranges elements by proton number.
• You can use the periodic table to work out electron configurations.
• Atomic radius decreases across a period.
• Ionisation energy generally increases across a period.