Question

often, to find breaks in trends and to understand why there are exceptions to what we expect, we need to study the electron configuration. what is the electron configuration of n? he2s² 2p³ ne 3s² 3s³ he 2s² 3p³

Explanation:

Step1: Determine the atomic number of N

Nitrogen (N) has an atomic number of 7.

Step2: Write the electron configuration using noble - gas shorthand

The noble gas before N in the periodic table is He (atomic number 2). So we start with [He].
The remaining number of electrons is \(7 - 2=5\).
The next sub - shells are \(2s\) and \(2p\). The \(2s\) sub - shell can hold 2 electrons and the \(2p\) sub - shell can hold 3 electrons. So the electron configuration is \([He]2s^{2}2p^{3}\).

Let's check the other options:

• For the option \([Ne]3s^{2}3s^{3}\), Ne has an atomic number of 10. If we use [Ne], we would need to subtract 10 from the atomic number of N (7), which gives a negative number of electrons. Also, the notation \(3s^{3}\) is incorrect as the \(s\) sub - shell can hold a maximum of 2 electrons.
• For the option \([He]2s^{2}3p^{3}\), after filling the \(2s\) sub - shell, the next sub - shell to be filled is \(2p\), not \(3p\).

Answer:

[A. [He]2s² 2p³]