Question #2f9e6

1 Answer
Mar 23, 2016


Since it has 13 protons it is an aluminium atom.


The atomic number, which is the number of protons defines the element, in this case aluminium. Since the number of electrons is the same as the number of protons, the atom is neutral.

The number of protons plus the number of neutrons gives the mass of the number of this particular isotope, being 25. But this is an unstable isotope of aluminium with a half-life of 7 seconds.