Question

how many neutrons does an atom of manganesese have

Answer 1

30 (see attached file)

Answer 2

If you are referring to the element Manganese, the number of neutrons should be 25. This is because the number of neutrons is the same as the number of protons in a non-isotopic form of Mn. This number is equal to the atomic number.

Answer 3

The simplest way of doing this for manganese, or indeed any element, is to use the periodic table. Taking manganese (Mn), if we look this up on the periodic table, then we see that it has:

- An atomic number of 25. This is the NUMBER OF PROTONS OR ELECTRONS THAT ARE IN AN ATOM OF MANGANESE. As an atom is neutral, the number of protons (positively charged species in nucleus of atom) and the number of electrons (negatively charged species orbiting nucleus) must be the same.
- An atomic mass number of 55 (when rounded up to a whole number, which we can do here). This is the NUMBER OF PROTONS (+ CHARGED) AND NEUTRONS (NEUTRAL) IN THE NUCLEUS OF THE ATOM OF MANGANESE.

So, we can say that:
NUMBER OF NEUTRONS = (NUMBER OF PROTONS AND NEUTRONS) - (NUMBER OF PROTONS)
or:
NUMBER OF NEUTRONS = ATOMIC MASS NUMBER - ATOMIC NUMBER.

So, knowing the atomic mass number and atomic number of the element, you can work out the number of neutrons in manganese.