Question

number of electrons present in m3- ion​

Answer 1

The specie is an anion so the number of electrons will be equal to atomic number + 3 electrons.

electrons in m3- ion =atomic no. + 3$e^{-} s$

Answer 2

The number of electrons with a certain number of ions can be calculated to atomic number.

Explanation:

Here the number of electrons present in m³⁻

If the atomic number is 7

As we know that the atomic number is the number of protons in a nucleus

-- Thus  here the number of protons will be 7

In a neutral atom the number of protons will be equal to the number of electrons

-- Thus the number of electrons = 7

Hence the required number of electrons in the given  m³⁻ ion

= 7 + 3

= 10

Number of electrons in the given  m³⁻ ion is equal to 10