A "FORCE" is required to cause acceleration or cause an object to move.
3.21e+11 is your answer for 321 millimeters in picometers. Hope this helps!
Answer: 22 neutrons
Explanation: 40 is the mass number = atomic mass = total number of protons and neutrons in atomic nucleus
18 is the number of protons in the nucleus of this atom
Then 40 - 18 = 22 neutrons
and this is Argon