Consider a hypothetical atom with an atomic number of 4 and a net electronic charge of + 1. It has 4 protons. How many neutrons does this atom have?

1 Answer
Jul 9, 2016

Answer:

We know that the atom is #"beryllium"# if #Z=4# (why?). The number of neutrons is likely #5#.

Explanation:

#Z", the atomic number"#, is the number of protons, massive positively charged particles present in the nucleus. #Z# defines the element, and if #Z=4#, the element beryllium is specified.

While beryllium has several isotopes, #""^9Be# is the most common, and certainly overwhelmingly abundant. Even at A level, however, (or even at 1st year undergraduate level), it would not be appropriate to ask a student which is the most stable beryllium nuclide.