An atom of silicon has a mass number of 28 and an atomic number of 14. how can you determine how many protons and how many neutrons are in this atom?

So the question ask to determine or what are the ways in determining how many neutrons and how many protons that is present in an atom of silicon that has a mass number of 28 and an atomic number of 14, base on that, I would say that the atomic number is the number of protons in an atom while the number of neutron is computed by subtracting atomic number and the mass number. 

An  atom  (ours, not carroll's) consists of a positively charged  nucleus, surrounded by one or more negatively charged particles called  electrons. the positive charges equal the negative charges, so the atom has no overall charge; it is electrically neutral. most of an atom's mass is in its nucleus; the mass of an electron is only 1/1836 the mass of the lightest nucleus, that of hydrogen. although the nucleus is heavy, it is quite small compared with the overall size of an atom. the radius of a typical atom is around 0.1 to 0.25 nanometres (nm), whereas the radius of a nucleus is about 10-6  nm.  *  if an atom were enlarged to the size of the earth, its nucleus would be only 200 feet in diameter and could easily rest inside a small football stadium.read more on -

The objects do not reach terminal velocity         there is not enough time from the time the object falls from when it hits the ground to achieve terminal velocity. an object must be placed higher to achieve terminal velocity in order to be in free fall.