The Rest-Mass Energy of an Electron Is
A) Zero $9.1 \times 10 ^ { - 31 } \mathrm {~kg}$

Multiple Choice

The rest-mass energy of an electron is

A) zero.
B) $9.1 \times 10 ^ { - 31 } \mathrm {~kg}$
C) $8.2 \times 10 ^ { - 14 } \mathrm {~J}$
D) $0.511 \mathrm { MJ }$