The acceleration of body is given 16.3m/s2 and the force is given 4.6 N then
We know,
Force=mass*acceleration
Then,
Mass=force/acceleration
Mass=4.6/16.3
Mass=0.28kg
Dominoes does because when you hit one, it knocks over the next one, and so on, so forth. The same type of pattern happens in a wave.
A and C Im pretty sure :)

Since the diameter of helium atom is approximately
, therefore the diameter of helium atom in nano meter,
