Group 2: Be, Mg, Ca, Sr, Ba, Ra. Configuration [noble gas] $ns^2$. Smaller, denser, harder, higher m.p. than corresponding Group 1 metals (stronger metallic bonding with 2 valence electrons). IE is higher than Group 1 but still low enough for ionic bonding. Always show +2 OS. Reactivity with water increases down: Be does not react, Mg reacts with hot water/steam, Ca onwards react with cold water (Ca(OH)2 + H2). All except Be and Mg give characteristic flame colours: Ca (brick red), Sr (crimson), Ba (apple green). Be and Mg ions are too small — their electrons are too tightly held for visible transitions. All Group 2 hydroxides are basic except Be(OH)2 (amphoteric).