When an atom of calcium loses two electrons, what is the resulting charge on the calcium ion?

• A. 2+
• B. 1+
• C. 2-
• D. 0

Answer: (A)

Verified step by step guidance

1. Recall that an atom is electrically neutral, meaning it has an equal number of protons (positive charges) and electrons (negative charges).
2. Calcium (Ca) has 20 protons and 20 electrons in its neutral state, so its net charge is zero.
3. When calcium loses two electrons, it loses two negative charges, but the number of protons remains the same (20 positive charges).
4. The resulting charge on the calcium ion is calculated by subtracting the number of electrons from the number of protons: \(\text{Charge} = +20 - 18 = +2\).
5. Therefore, the calcium ion formed after losing two electrons has a charge of \$2+$.