Question

in class, students are asked to evaluate the electron configuration 1s²2s²2p⁶3s²4p¹. two student responses are below.
student 1: this is an impossible electron configuration. electrons fill the lowest energy levels first, so the electron shown in the 4p orbital should actually be in 3p.
student 2: this electron configuration shows an atom in an excited state. the electron in the 4p sublevel exists in the 3p sublevel in its ground - state, but the atom absorbed enough energy that this electron moved to a higher energy level, 4p.

1. **with which student do you agree, and why?

for each of the following atoms, write the full electron configuration.

1. **nitrogen atom

for each of the following atoms, write the abbreviated or noble gas electron configuration.

1. *chlorine atom

for each of the following atoms, write the orbital notation.

1. oxygen atom

Explanation:

Step1: Recall electron - filling order

Electrons fill orbitals in order of increasing energy. The order is \(1s<2s < 2p<3s<3p<4s<3d<4p\cdots\). In the given configuration \(1s^{2}2s^{2}2p^{6}3s^{2}4p^{1}\), the \(4p\) orbital is filled before the \(3p\) orbital is completely filled. This indicates an excited - state electron configuration.

Step2: Analyze student responses

Student 1 correctly states that electrons fill the lowest energy levels first and that the electron in the \(4p\) orbital should be in the \(3p\) orbital in the ground - state. Student 2 is incorrect because the configuration is not in the ground state as stated.

Step3: Write nitrogen's electron configuration

Nitrogen has 7 electrons. Using the electron - filling order, its full electron configuration is \(1s^{2}2s^{2}2p^{3}\).

Step4: Write chlorine's noble - gas electron configuration

Chlorine has 17 electrons. The nearest noble gas is neon (\(Ne\)) which has 10 electrons. So the noble - gas electron configuration of chlorine is \([Ne]3s^{2}3p^{5}\).

Step5: Write oxygen's orbital notation

Oxygen has 8 electrons. The orbital notation is:

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Answer:

1. I agree with Student 1. Electrons fill the lowest energy levels first, and the given configuration \(1s^{2}2s^{2}2p^{6}3s^{2}4p^{1}\) is an excited - state configuration as the \(4p\) orbital is filled before the \(3p\) orbital is full.
2. \(1s^{2}2s^{2}2p^{3}\)
3. \([Ne]3s^{2}3p^{5}\)

4.

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