An indium ion with a charge of -3 is formed. How many protons and electrons does this ion have?

• A. 49 protons and 52 electrons
• B. 52 protons and 49 electrons
• C. 49 protons and 46 electrons
• D. 46 protons and 49 electrons

Answer: (A)

Verified step by step guidance

1. Identify the atomic number of indium (In) from the periodic table, which gives the number of protons in a neutral indium atom.
2. Recall that the number of protons in an element does not change when it forms an ion; only the number of electrons changes.
3. Since the ion has a charge of -3, it means the ion has gained 3 extra electrons compared to the neutral atom.
4. Calculate the number of electrons in the ion by adding 3 to the number of protons (electrons in neutral atom) because of the -3 charge.
5. Summarize the result: the ion has the same number of protons as neutral indium and the number of electrons equals protons plus 3.