Chapter 2 - Atoms, Molecules, and Ions - Questions and Problems - Page 82: 2.47

${^{28}_{14}Si}$

The element that has 14 protons in its nucleus is Silicon (Si) . We find this in periodic table of the elements, as atomic number (Z) is given in this table. ( Z is the number of protons). Mass number is the total number of protons and neutrons. In this case it is 28 ( 14 + 14). So the nuclide symbol for the nucleus that contains 14 protons and 14 neutrons, should be ${^{28}_{14}Si}$ .