How many electrons are in the outermost energy level of an electrically neutral atom of aluminum?

To determine the number of electrons in the outermost energy level of an electrically neutral atom of aluminum, follow these steps:

1. Identify the atomic number of aluminum. The atomic number of aluminum is 13, which means it has 13 protons and, in a neutral atom, 13 electrons.

2. Determine the electron configuration of aluminum. The electron configuration describes the distribution of electrons in the atom's energy levels (shells). For aluminum, the electron configuration is: 1s² 2s² 2p⁶ 3s² 3p¹

3. Identify the outermost energy level. The outermost energy level is the highest principal quantum number (n) that contains electrons. For aluminum, the highest principal quantum number is 3.

4. Count the electrons in the outermost energy level. In the electron configuration of aluminum, the electrons in the third energy level (n=3) are: 3s² 3p¹

   Adding these together, we get: 2 (from 3s²) + 1 (from 3p¹) = 3

Therefore, there are 3 electrons in the outermost energy level of an electrically neutral atom of aluminum.