Electronic Configuration: 1s22s22p4

The given electronic configuration of an atom is 1s22s22p4. This configuration represents the ground state electronic configuration of Oxygen atom. The electronic configuration indicates the number of electrons in each orbital of the atom.

Term Symbols: 1S and 3P

For the given electronic configuration, two of the possible term symbols are 1S and 3P. These term symbols represent the total angular momentum quantum number (L) and the total spin quantum number (S) of the atom. The possible combinations of L and S for the given electronic configuration are:

- L=0, S=1/2 (1S)
- L=1, S=1/2 (3P)

Remaining Term Symbol

The remaining term symbol for the given electronic configuration can be determined using the following steps:

1. Determine the maximum value of L based on the number of electrons in the outermost shell. In this case, there are 4 electrons in the outermost shell, which corresponds to the p subshell. Therefore, the maximum value of L is 1.

2. Determine the possible values of S based on the number of unpaired electrons. In this case, there are 2 unpaired electrons in the p subshell, which corresponds to a spin multiplicity of 2S+1=3. Therefore, the possible values of S are 1/2 and 3/2.

3. Write down the possible term symbols based on the combinations of L and S. The possible term symbols are:

- 1P, 3P (L=1, S=1/2 or 3/2)
- 1D, 3D (L=2, S=1/2 or 3/2)
- 1F, 3F (L=3, S=1/2 or 3/2)

Therefore, the remaining term symbol for the given electronic configuration is either 1P, 3P, 1D, 3D, 1F or 3F. The actual term symbol depends on the number of unpaired electrons and their distribution in the subshells.