boron-10 has an atomic number of 5. how many neutrons are in this isotope? 0 neutrons, 2 neutrons, 5 neutrons, 10 neutrons.

I say 5

right.

To determine the number of neutrons in an isotope, you need to subtract the atomic number from the mass number. The atomic number represents the number of protons in an atom, while the mass number represents the total number of protons and neutrons.

In this case, boron-10 has an atomic number of 5, which means it has 5 protons. The mass number is also 10, as indicated by the isotope name.

To calculate the number of neutrons, subtract the atomic number (protons) from the mass number (protons + neutrons).

Number of neutrons = Mass number - Atomic number
Number of neutrons = 10 - 5
Number of neutrons = 5

Therefore, boron-10 contains 5 neutrons. Your answer is correct.