Problem 58 - Chemistry

Question

What is the symbol of an ion with 16 protons, 18 neutrons, and 18 electrons? What is the symbol for an ion that has 16 protons, 16 neutrons, and 18 electrons?

Step-by-Step Solution

Answer

The symbols for the two ions are \(\ce{^{34}_{16}S^{2-}}\) and \(\ce{^{32}_{16}S}\).

Step 1: Determine the element from the number of protons

The number of protons defines the element. In both cases, we have 16 protons, which corresponds to the element sulfur (S). The symbol for sulfur is \(S\).

Step 2: Calculate the charge of the ion

The charge of an ion is the difference between the number of protons and electrons. 1. For the ion with 16 protons and 18 electrons: Charge = Number of protons - Number of electrons = 16 - 18 = -2 2. For the ion with 16 protons and 16 electrons: Charge = Number of protons - Number of electrons = 16 - 16 = 0

Step 3: Determine the mass number

The mass number of an atom is the sum of its protons and neutrons. 1. For the ion with 16 protons and 18 neutrons: Mass number = Number of protons + Number of neutrons = 16 + 18 = 34 2. For the ion with 16 protons and 16 neutrons: Mass number = Number of protons + Number of neutrons = 16 + 16 = 32

Step 4: Write the symbol for each ion

1. For the ion with 16 protons, 18 neutrons, and 18 electrons: The symbol is \(\ce{^{34}_{16}S^{2-}}\) 2. For the ion with 16 protons, 16 neutrons, and 18 electrons: Since the ion has no charge, it is not an ion but a neutral atom. The symbol is \(\ce{^{32}_{16}S}\)