Which of the following electron configuration represents an atom in the excited state?
1s22s22p14s1
1s22s22p63s23p1
1s22s22p5
1s22s22p63s2
To determine which electron configuration represents an atom in the excited state, we need to identify the configuration that deviates from the usual pattern of filling the electron orbitals in increasing order of energy levels.
Let's analyze each option:
1. 1s22s22p14s1: This configuration follows the normal pattern of filling orbitals in increasing order of energy. Therefore, it does not represent an excited state.
2. 1s22s22p63s23p1: Notice that the 3s and 3p orbitals are partially filled (3s23p1), indicating the presence of unpaired electrons in higher energy orbitals. This configuration represents an atom in the excited state.
3. 1s22s22p5: This configuration also follows the normal pattern of filling orbitals, and it does not have any electrons in higher energy orbitals. Therefore, it does not represent an excited state.
4. 1s22s22p63s2: Similar to option 3, this configuration follows the normal pattern of filling orbitals, and it does not have any electrons in higher energy orbitals. Thus, it does not represent an excited state.
In conclusion, the option that represents an atom in the excited state is 1s22s22p63s23p1.