Question

write the electron configuration for a nitrogen anion with a charge of -2.

Explanation:

Step1: Determine the number of electrons in neutral nitrogen atom

Nitrogen has an atomic number of \(7\), so a neutral nitrogen atom has \(7\) electrons.

Step2: Calculate the number of electrons in \(N^{2 -}\)

Since the charge is \(- 2\), the number of electrons is \(7+2 = 9\)

Step3: Write the electron configuration

Using the Aufbau principle (\(1s<2s < 2p\)), for \(9\) electrons:

• Fill \(1s\) first: \(1s\) can hold \(2\) electrons, so \(1s^{2}\)
• Then fill \(2s\): \(2s\) can hold \(2\) electrons, so \(2s^{2}\)
• Remaining \(9-(2 + 2)=5\) electrons go to \(2p\) (since \(2p\) can hold up to \(6\) electrons), so \(2p^{5}\)

Answer:

\(1s^{2}2s^{2}2p^{5}\)