Chapter 1 - Exercises - Page 51d: 50

$^{34}_{16}$S$^{2-}$ $^{32}_{16}$S$^{2-}$

An ion with 16 protons, means that ion is that of an element that has atomic number 16, which is sulfur. We add 16 protons to 18 neutrons to get the mass number, which is 34. In a neutral atom, the number of electrons equals the number of protons. In this case, the number of protons and electrons are not equal; we have 16 protons but 18 electrons. Because we have two more electrons than protons, we have an ion with two extra negative charges (2-). We write the mass number as a superscript to the left of the chemical symbol and the atomic number as a subscript also to the left of the chemical symbol. We write the charge of the ion as a superscript to the right of the chemical symbol. The complete symbol for this ion is $^{34}_{16}$S$^{2-}$. An ion with 16 protons means that the ion is that of an element that has atomic number 16, which is sulfur. We add 16 protons to 16 neutrons to get the mass number, which is 32. In a neutral atom, the number of electrons equals the number of protons. In this case, the number of protons and electrons are not equal; we have 16 protons but 18 electrons. Because we have two more electrons than protons, we have an ion with two extra negative charges (2-). We write the mass number as a superscript to the left of the chemical symbol and the atomic number as a subscript also to the left of the chemical symbol. We write the charge of the ion as a superscript to the right of the chemical symbol. The complete symbol for this ion is $^{32}_{16}$S$^{2-}$.