Valency
Combining capacity of elements
Classification Basis: Elements with similar valency often form similar compounds. Higher valency means more bonds.
Atomic Size
Atomic radius in picometers
Classification Basis: Size decreases across periods, increases down groups. Affects chemical properties.
Electronegativity
Ability to attract electrons
Classification Basis: Higher electronegativity means stronger electron attraction. Affects bond type and polarity.
Chemical Reactivity
Tendency to participate in reactions
Classification Basis: Measures how readily elements undergo chemical reactions. Higher values = more reactive.