Are alkali metals softer or harder than other metals?

Answer 1

The softness of alkali metals has to do with metallic bonding in terms of bonding and anti bonding orbitals. In molecular orbitals, there are the s, p, d orbitals with corresponding anti-bonding orbitals. For alkali metals, the s orbital is only partially filled. This means that the bonds between each atom are weak because only a cloud of s-orbital electrons are holding them together. As we move right across the Periodic Table the strength of metals reach a maximum at about group 7-8. This is because at this point anti-bonding and bonding orbitals are both partially filled and this maximizes the amount of unpaired electrons that participate in the electron cloud that holds metallic bonds together. As we proceed further right (toward Au) the bonds become weaker because the bonding and anti-bonding orbitals begin to fill and pair up. This means these electrons do not participate in the electron cloud of metallic bonding. Thus a weaker bond (softer metal) is formed.

Answer 2

Alkali metals (Group I) readily lose 1 electron to form positive ions. Compared to alkali earth metals (Group II), alkali metals are more reactive because they only need to lose 1 valence electron to achieve stable electronic configuration. Unlike the metals in Group II, which need to lose 2 electrons. As such, they need to overcome the force exerted by the proton nucleus on 2 electrons instead of just one (for alkali metals).

As such, Group II metals have a higher activation energy and thus is less likely to react as compared to alkali metals.

Answer 3

The melting and boiling point of the alkali metals are low indicating week metallic bonding due to the presence of only a single valence electron in them. Hence alkali metals are soft.

Answer 4

generally they are soft. they are softer than other metals.

Answer 5

They are generally softer.