Can you electrically polarize gas? If you put a non-polar gas like $\rm CO_2$ in a positive electric field, Will it get polarized? What will be the force the molecules get as its attracted to the positive field?
 A: CO$_2$ is a molecule with structure $C{\bf =}O{\bf =}C$ so that it's linear. In each single $C{\bf =}O$ the oxygen atom is more electronegative than the carbon atom.
That is, there are two individual dipoles that point outward from the carbon atom to the oxygen atom. But because the dipoles have equal strength, and point in opposite directions (linear molecule), the dipole moments cancel out so that the overall polarity of the CO$_2$ molecule is zero.
Because it has no polarity, it will not tend to align with a uniform electric field (provided it is not very large, say up to $5-10Vm^{-1}$) when placed in one. Only polar molecules will do this.
But for larger electric fields, this may not be the case, and the result is that the molecules may experience a force.
A: Isotropic polarizability of CO2 is, roughly, 15 atomic units (J. Phys. Chem. A 2000, 104, 11355-11361), and atomic unit of dipole polarizability is $1.64877727436 \times 10^{-41} C^2 m^2 J^{-1}$. The force acting on a dipole in non-uniform electric field
