Final answer:
The electron configuration 1s² 2s² 2p⁶ 3s² 3p⁴ represents a ground-state atom of oxygen (b).
Step-by-step explanation:
The electron configuration 1s² 2s² 2p⁶ 3s² 3p⁴ represents a ground-state atom of oxygen (b).
The electron configuration is a way to represent the arrangement of electrons in an atom's energy levels or orbitals. In this case, the electron configuration 1s² 2s² 2p⁶ 3s² 3p⁴ has a total of 16 electrons, which matches the number of electrons in an oxygen atom. The superscript numbers indicate the number of electrons in each orbital. For example, 2p⁶ means there are 6 electrons in the 2p orbital.
By comparing the given electron configuration to the known electron configurations of elements, we can conclude that the electron configuration matches that of oxygen (atomic number 8). Therefore, the answer is oxygen (b).