Final answer:
The electron configuration 1s²2s²2p⁶3s² corresponds to magnesium (Mg), which is element number 12 on the periodic table with a total of 12 electrons filling its orbitals up to the 3s level.
Step-by-step explanation:
The electron configuration 1s²2s²2p⁶3s² describes the distribution of electrons in an atom's orbitals up to the third energy level. The 's' and 'p' labels refer to the shape of the orbitals where these electrons are located, and the superscript numbers indicate how many electrons are in each orbital.
Based on this configuration, the atom in question is magnesium (Mg), which is the twelfth element on the periodic table. Magnesium has a total of 12 electrons, which fill the 1s, 2s, and 2p orbitals completely, and add the last two electrons in the 3s orbital, following the Aufbau principle.