Which particle contains the greatest number of electrons?

1. Na

2. Na+

3. F

4. F-

Na

Explanation:

The atomic number of sodium is 11 while that of fluorine is 9. Thus the number of electrons in sodium are 11 while in fluorine are 9.

The cation of an atom form when atom lose electron.

Na → Na⁺ + e⁻

it means the cation of sodium loses its one outer most electron. Thus it has 10 electron while Na atom has 11 electron.

On other hand fluorine has 9 electrons.

The anion of an atom form when it gain electron.

F + e⁻ → F⁻

Thus the number of electrons in given species are,

Na = 11

Na⁺ = 10

F = 9

F⁻ = 10

Na has more number of electrons.