Question #3b9ca

1 Answer
May 17, 2017



The number of protons in an atom of the element defines that element's atomic number, i.e. a strontium atom will always have 38 protons in the nucleus. The number of neutrons and electrons, however, can change. Atoms can either donate or receive electrons (some elements, such as carbon and nitrogen, can do both) to become ions, and an atom of the same element with a different number of neutrons is called an isotope.