Which of the following electron configurations represent an excited state?

1s22s22p1
1s22s22p63s2
1s1
1s22s12p63s1
1s12s22p63p3
1s22s22p23d1
1s22s22p64s1

1s22s22p23d1

An excited state electron configuration usually involves electrons being promoted to higher energy levels. We can determine if an electron configuration represents an excited state by comparing it to the electron configuration of the ground state for the element in question.

The ground state electron configuration for hydrogen (H) is 1s1. The electron configuration for an excited state would involve an electron being promoted to a higher energy level, such as 2s or 2p.

Looking at the given electron configurations:
1. 1s22s22p1 - This electron configuration represents an excited state since there is an electron in the 2p orbital, indicating promotion from the 2s to 2p orbital.

2. 1s22s22p63s2 - This electron configuration is not an excited state and represents the ground state for sulfur (S).

3. 1s1 - This electron configuration is not an excited state and represents the ground state for hydrogen (H).

4. 1s22s12p63s1 - This electron configuration is not an excited state and represents the ground state for phosphorus (P).

5. 1s12s22p63p3 - This electron configuration represents an excited state since there are three electrons in the 3p orbital, indicating promotion from the 2s and 2p orbitals to the 3p orbital.

6. 1s22s22p23d1 - This electron configuration represents an excited state since there is an electron in the 3d orbital, indicating promotion from the 2p to 3d orbital.

7. 1s22s22p64s1 - This electron configuration is not an excited state and represents the ground state for potassium (K).

Therefore, the electron configurations that represent an excited state are: 1s22s22p1, 1s12s22p63p3, and 1s22s22p23d1.

To determine if an electron configuration represents an excited state, we need to compare it to the electron configuration of the element in its ground state.

The ground state electron configuration for an atom or ion can be determined by following the Aufbau principle, which states that electrons fill orbitals from the lowest energy level to the highest energy level.

Let's go through each option and compare them to the known ground state electron configurations:

1. 1s22s22p1: This configuration represents a nitrogen (N) atom, which is in its ground state.

2. 1s22s22p63s2: This configuration represents a silicon (Si) atom, which is in its ground state.

3. 1s1: This configuration represents a hydrogen (H) atom in its ground state.

4. 1s22s12p63s1: This configuration does not correspond to a known element's electron configuration. It suggests the presence of only one electron in the second shell (2s orbital), which is not typical.

5. 1s12s22p63p3: This configuration does not correspond to a known element's electron configuration. It suggests the presence of three unpaired electrons in the third shell (3p orbital), which is not typical.

6. 1s22s22p23d1: This configuration represents a chromium (Cr) atom, which is in an excited state. The ground state configuration for chromium is 1s22s22p63s23p64s23d4, but this configuration has one electron in the 3d orbital instead of two.

7. 1s22s22p64s1: This configuration represents a potassium (K) atom, which is in its ground state.

From the options given, option 6 (1s22s22p23d1) represents an electron configuration that is in an excited state.