as sodium has metallic bond in between there atoms which is a strong bond then why it is soft ?
Sodium only has one valence electron
Sodium only has one valence electron. So, in metallic bonding, it can only donate one electron to be delocalized throughout the structure.
In metallic bonding, the actual bonding is the electrostatic force between the positive cations and the delocalized electrons. Since there is only one electron for each ion, sodium as a pure metal is relatively soft, especially compared to other metals that have more than one valence electron.