How many protons and neutrons are in an atom of Mo-94?

Question

Owen Ambrose · Accepted Answer

#94# protons and neutrons.

This is a great example of a question that actually provides you with the answer. The quick answer here is that there are #94# protons and neutrons in a molybdenum-94 isotope, #""^94"Mo"#. That is the case because an element's isotopes are distinguished using their mass number, which is added to the name of the isotope using a hypen. As you know, the mass number, #A#, tells you the number of nucleons present in the nucleus. A nucleon is simply a proton or a neutron. This means that the mass number of a given isotope essentially tells you how many protons and neutrons are present in its nucleus. In your case, molybdenum-94 has a mass number of #94#, which means that it contains #94# protons and neutrons in its nucleus. To find the specific number of protons and of neutrons, grab a periodic table and look for molybdenum, #"Mo"#. You'll find the element listed in period 5, group 6. Its atomic number, #Z#, which tells you how many protons are present in the nucleus, is equal to #42#. This means that the nucleus of any isotope of molybdenum will contain #42# protons. This leaves you with #"no. of neutrons" = A - Z# #"no. of neutrons" = 94 - 42 = "52 neutrons"#

Luna Chen · Answer

undefined An atom of Mo-94 has 42 protons and 52 neutrons.