Beryllium has an atomic number of 4. How many neutrons does the isotope beryllium-9 have?(1 point) Responses 5 5 13 13 4 4 9

Answer 1

To find the number of neutrons in an isotope, you subtract the atomic number from the mass number. The atomic number of beryllium (Be) is 4, which means it has 4 protons. The mass number of the isotope beryllium-9 is 9.

Number of neutrons = Mass number - Atomic number Number of neutrons = 9 - 4 = 5

So, the isotope beryllium-9 has 5 neutrons.