WAEC - Chemistry (2007 - No. 1)
When sodium atom form the ion Na+,
it gains one proton
it achieves a noble gas configuration
its atomic number increases
it gains one electron
Explication
When the sodium atom forms an ion, Na+ it loses one electron, i.e. it achieves a noble gas electronic configuration. It will lose one of its 11 electrons to have 10 electrons like neon.
\(Na - e^- → Na^+\)
Na → \(Na^+ + e^-\)
\(Na - e^- → Na^+\)
Na → \(Na^+ + e^-\)