The mass number of fe2+ is 56. how many neutrons are there in a single fe2+ atom? 28 30 56 58

Answer is: 30 neutrons.

Z = p⁺; atomic number.  

Atomic number is the number of protons, which is characteristic of a chemical element, iron (Fe) is an element with atomic number 26.

In neutral atom, number of protons is equal to number of electrons, but Fe²⁺ is cation who lost two electrons.

A = p⁺ + n°; mass number is the total number of protons and neutrons in a nucleus.  

A(Fe²⁺) = 56.

p⁺(Fe²⁺) = 26.

n°(Fe²⁺) = A(Fe²⁺) - p⁺(Fe²⁺).

n°(Fe²⁺) = 56 - 26.

n°(Fe²⁺) = 30.

explanation:

i think option no d is the correct answer

d.) circle motion requires a force to give it a centripetal acceleration.