Electron configuration: It is formed by the combination of two hydrogen atoms $(1s^1)$. The total number of electrons in the $H_2$ molecule is $2$.
In the $H_2$ molecule,the molecular orbitals are $\sigma_{1s}$ and $\sigma_{1s}^*$.
Therefore,the electron configuration of the $H_2$ molecule is $(\sigma_{1s})^2 (\sigma_{1s}^*)^0$.
Bond order: The number of electrons in the bonding molecular orbital $(BMO)$ $\sigma_{1s} = 2$ and in the antibonding molecular orbital $(ABMO)$ $\sigma_{1s}^* = 0$.
Therefore,Bond order $= \frac{N_b - N_a}{2} = \frac{2 - 0}{2} = 1$.
This means two $H$ atoms are bonded together by a single covalent bond.
Magnetic property: In the $H_2$ molecule,there are no unpaired electrons; all electrons are paired. Therefore,the $H_2$ molecule is diamagnetic.