The atomic number of magnesium mg is 12. the symbol for a magnesium ion is mg2+. deduce the number of electrons in a magnesium ion 12 =

The number of electrons in Magnesium ion is 10.

Explanation:

Given element is Magnesium whose atomic number is 12.

The atomic number of an element  tells the number of electrons in a neutral atom of the element. So the number of electron is also 12.

Now we will find out the electron configuration for Mg,

Electron configuration for Mg =

That means the number of electrons for K,L,M shell is 2,8,2.

Any element gain or lose electrons and forms ion to become stable. In case of Magnesium there are 2 electrons in its outer most shell, so it loses 2 electrons and forms Magnesium ion.

Number of electrons in Magnesium ion = Number of electrons in Magnesium atom - Number of losed electrons

Number of electrons in Magnesium ion =

Hence the number of electrons in Magnesium ion is 10.