$s p^2, s p, s p^3 d$

$s p, s p^2, s p^3$

$s p^3, s p, s p^3 d$

$s p^2, s p^3, d s p^2$

greater hardness

higher boiling points

smaller ionic radii

lower ionisation enthalpy

$\mathrm{Mn}^{3+}$ is oxidising agent while $\mathrm{Cr}^{2+}$ is reducing agent.

Both are reducing agents.

$\mathrm{Mn}^{3+}$ is reducing agent while $\mathrm{Cr}^{2+}$ is oxidising agent.

Both are oxidising agents.