How many protons and electrons are in each of the following ions? (d) Au3+

Verified step by step guidance

1. Step 1: Identify the atomic number of the element. The atomic number of an element is equal to the number of protons in its nucleus. For gold (Au), the atomic number is 79, which means there are 79 protons.
2. Step 2: Determine the charge of the ion. The charge of the ion is given as 3+. This means that the ion has lost 3 electrons.
3. Step 3: Calculate the number of electrons. The number of electrons in a neutral atom is equal to the number of protons. However, since the Au ion has a 3+ charge, it has 3 fewer electrons than protons. Therefore, subtract 3 from the number of protons to find the number of electrons.
4. Step 4: So, the Au3+ ion has 79 protons and 76 electrons.

Key Concepts

Atomic Structure

Atoms consist of protons, neutrons, and electrons. Protons are positively charged particles found in the nucleus, while electrons are negatively charged and orbit the nucleus. The number of protons defines the element, and in a neutral atom, the number of electrons equals the number of protons.

Ions

Ions are atoms or molecules that have gained or lost one or more electrons, resulting in a net charge. Cations are positively charged ions formed by losing electrons, while anions are negatively charged ions formed by gaining electrons. The charge of an ion indicates the difference between the number of protons and electrons.

Gold Ion (Au3+)

The Au3+ ion indicates that a gold atom has lost three electrons, resulting in a +3 charge. Gold has an atomic number of 79, meaning it has 79 protons. Therefore, in the Au3+ ion, there are 79 protons and 76 electrons (79 protons - 3 electrons).