Question

Which of the following is the ground state electron configuration for aluminum (Al)?

A) 2-8-3
B) 2-5
C) 2-8-8-2
D) 2-8-7

Answer 1

The ground state electron configuration for aluminum (Al) is 1s²2s²2p⁶3s²3p¹, which includes the placement of 13 electrons according to the increasing energy levels of subshells.

Step-by-step explanation:

The ground state electron configuration for aluminum (Al) is 1s²2s²2p⁶3s²3p¹. To write the electron configuration, you start at the beginning of the periodic table and fill the orbitals in the order of increasing energy. Aluminum has an atomic number of 13, meaning it has 13 electrons to place in orbitals.

1. Place two electrons in the 1s subshell (1s²).
   
2. Move to the second period and place two electrons in the 2s subshell (2s²) and six electrons in the 2p subshell (2p⁶).
   
3. Move to the third period and place the next two electrons in the 3s subshell (3s²) and the last one electron in the 3p subshell (3p¹).

The correct notation reflects the filling order of the orbitals and corresponds to energy levels and subshells. It uses superscript numbers to indicate the number of electrons in each subshell. The above steps result in the electron configuration for aluminum (Al) being 1s²2s²2p⁶3s²3p¹, which matches option A of the original question if it were written in the standard electron configuration format.