The species which is not paramagnetic among the following is

Options

A. `Cl^-`
B. `Be`
C. `Ne^(2+)`
D. `As^+`

Answer

A

Explanation

Paramagnetic character is based upon presence of unpaired electron.
`.17Cl^(-)=1s^2 , 2s^2 2p^6, 3s^2 3p_x^2 3p_y^2 3p_z^2`
In `Cl^-` no unpaired electron , so it is in nature diamagnetic
`._4Be=1s^2 , 2s^1 2p_x^1`
`._10Ne^(2+)=1s^2 , 2s^2 2p_x^2 2p_y^1 2p_z^1`
`._33As^(+)=1s^2, 2s^2 2p^6 , 3s^2 3p^6 3d^10 , 4s^2 4p_x^1 4p_y^1 4p_z^0`
While all others have unpaired electron, so they are paramagnetic in nature.