The s-Block Elements-Solutions

1) What are the common physical features of alkali metals?

Solution-

i) Common physical features of alkali metals:

i) Alkali metals are silvery white, soft and light metals.

ii) They have low density , which increases from Li to Cs down the group.

iii) The general outer electronic configuration of all alkali metals in ns¹ (n= 2 to 7).

iv) The atoms of alkali metal have large atomic size in a particular period. The atomic size increases from Li to Cs down the group due to addition of extra shell from element to the next.

v) They have low ,melting and boiling points due to weak metallic bonding.

vi) They have low ionisation enthalpy due to large atomic size. The ionization enthalpy decreases down the group from Li to Cs as atomic size increases.