Which of the following is the correct symbol for the carbon isotope that contains seven neutrons?

• A. C-12
• B. C-13
• C. C-13
• D. C-14

Answer: (C)

Verified step by step guidance

1. Recall that the isotope notation C-\(A\) indicates a carbon atom with a mass number \(A\), where the mass number is the sum of protons and neutrons in the nucleus.
2. Know that carbon has an atomic number \(Z = 6\), which means every carbon atom has 6 protons.
3. Use the relationship: \(\text{Number of neutrons} = \text{Mass number} - \text{Number of protons}\).
4. For each isotope option, calculate the number of neutrons by subtracting 6 (protons) from the mass number: for example, for C-13, neutrons = 13 - 6 = 7.
5. Identify the isotope whose neutron count matches 7; this corresponds to C-13, making it the correct symbol for the carbon isotope with seven neutrons.