Physicists often use a different unit of energy, the electron volt, when dealing with energies at the atomic level. one electron volt, abbreviated ev, is defined as the amount of kinetic energy gained by an electron upon accelerating through a 1.0 v potential difference.

The answer would be true!

The correct answer is b, social stratification is needed for a society to exist. marxist theory regarding social stratification is that due to the differing economic capacities among people in society, a natural separation occurs between those that own the means of production and those that sell their labour in the production chain. 

The answer is number 4.