What is the total number of protons, neutrons, and electrons in a neutral atom of cadmium-112 (Cd-112)?

• A. 160
• B. 164
• C. 112
• D. 48

Answer: (B)

Verified step by step guidance

1. Identify the atomic number (Z) of cadmium (Cd), which represents the number of protons in the atom. For cadmium, Z = 48.
2. Recognize that in a neutral atom, the number of electrons equals the number of protons. Therefore, the number of electrons is also 48.
3. Determine the mass number (A) of the isotope, which is given as 112 for Cd-112. The mass number is the sum of protons and neutrons.
4. Calculate the number of neutrons by subtracting the atomic number from the mass number: \(\text{neutrons} = A - Z = 112 - 48\).
5. Find the total number of protons, neutrons, and electrons by adding them together: \(\text{total} = \text{protons} + \text{neutrons} + \text{electrons} = 48 + (112 - 48) + 48\).