As others have said, it depends on the atom. Check your periodic table - it lists the atomic weight and the atomic number (which is the number of protons). Subtract one from the other and you know how many neutrons the atom contains.
Of course, it's not _quite_ that simple - some atoms have isotopes that have more or fewer neutrons in the nucleus.
lol, uhm like rinyasuko said, depends on the atom you're talking about...
do you have any more information? like the atomic mass or something?
It usually depends on what element. You are suppose to subtract the mass number by the protons and then you'll get how many neutrons there are
what I've learned and grace this I'm only an 8th grade; but it depends on what kind of atom of an element you are talking about
it depends on the atomic mass, you take that and subtract the number of protons and there is you number of neutrons!!
Atomic weight - atomic number = neutrons
That should work for the basic elements.