Compounds of unipositive ions of alkali metals are paramagnetic.
Alkali metals have low density.
All alkali metals are silvery white and soft.
Alkali metals are most electropositive elements.
Solution
Alkali metals are soft and can be cut by knife.
Alkali metals have low density-Lithium, sodium and potassium float on water.
They have low ionization energies and their atoms readily lose the valence electron hence they are most electropositive elements.
Alkali metal salts are diamagnetic.