Answer the following:
a. Which of the following has density greater than water ? `Li, Na, K, Cs`.
b. Arrange K, Li, Rb in other of increasing electrode potential.
c. Arrange Na, Li, K and Cs in increasing order of metallic bond.
d. Which among Na, K, Cs and Li forms stable hydride ?
e. On reacting eith oxygen, potassium can form `K_(2)O`, `KO_(2)` and `K_(2)O_(2)`. Is it correct ?
f. Give the name of the hardest alakli metal.
g. Arrange the following in order orf increasing polarising albility.
`Li^(o+), Na^(o+), K^(o+), Cs^(o+)`
h. Mention some of the properties of alkali metals which increse down the group.
i. Mention some of the properties of alkali metals which decrease down the group.

Explanation

a. Lithium
b. `Li gt Rb gt K`
c. `Li lt Na lt K lt Rb`
d. Li
e. Yes, the statement is correct.
f. Lithium
`Cs^(o+) lt K^(o+) lt Na^(o+) lt Li^(o+)`
h. Electropositive or metallic character, softness, mallaebility, ductillity, atomic size or radii.
i. EN, IE, hydroation enthalpy `(Delta_(Hyd)H^(Θ))` and electrode potential.