Question

1. the mass number for the radioisotope carbon - 13 is:

a. 6
b. 7
c. 12
d. 13

Explanation:

The mass number of an isotope is indicated by the number in its name. For carbon - 13, the number 13 represents the mass number. The mass number is the sum of protons and neutrons in an atom's nucleus. Carbon has 6 protons (as its atomic number is 6), and for carbon - 13, neutrons = 13 - 6 = 7, but the mass number is still 13.

Answer:

d. 13