Question

The atomic mass of carbon-13 is 13. It has six protons. How many neutrons does this isotope have?

Answer 1

Carbon-13 will have 6 protons (because it is carbon), 6 electrons, and 7 neutrons. Isotopes have a different number of neutrons.

Answer 2

Atomic mass is the given by the sum of the number of protons and number of neutron in the nucleus of the atom.

A = P + N

where A = atomic mass of the atom

P = number of protons in the nucleus of the atom

N = Number of neutrons in the nucleus of the atom

Given that :

A = atomic mass = 13

P = number of protons in the nucleus = 6

N = ?

Using the equation

A = P + N

13 = 6 + N

N = 13 - 6

N = 7

hence the isotope has 7 neutrons