How many neutrons are in roentgenium?

Answer 1

Roentgenium-272 has 161 neutrons.

Number of neutrons = Atomic Mass of an isotope - Atomic number of the element

The atomic number of roentgenium is 111, but Rg has many isotopes each with a different atomic mass and number of electrons.

Answer 2

Roentgenium has 111 protons and 161 neutrons.

Answer 3

Roentgenium has 111 protons an 111 electrons.

Number of neutrons = Atomic mass of a given isotope of Rg - 111

Answer 4

For each isotope of Rg the number of neutrons is different. Number of neutrons = Mass number of an Rg isotope - 111