The Total solution for NCERT class 6-12
Whichof the alkali metal is having least melting point?
(a)Na (b) K (c) Rb (d) Cs
Atomicsize increases as we move down the alkali group. As a result, the bindingenergies of their atoms in the crystal lattice decrease. Also, the strength ofmetallic bonds decreases on moving down a group in the periodic table. Thiscauses a decrease in the melting point. Among the given metals, Cs is thelargest and has the least melting point.