Question

An atom contains 15 neutrons and has a mass number of 30. What is its atomic number? How did you determine the atomic number?

Answer 1

15

Step-by-step explanation:

The mass number is defined as the total number of protons and neutrons. The atomic number is total number of protons. And since we have the mass number and number of neutrons, we can use simple subtraction (30 - 15) to find that the atomic number is 15.