Question

1. when you add the electrons in each energy level, the sum represents the total number of ______, which is the same as the number of ____ and the same as the ____ ____. 9. aluminum has electrons in how many energy levels? ______

Explanation:

Question 8

In an atom, the sum of electrons in each energy level gives the total number of electrons. In a neutral atom, the number of electrons is equal to the number of protons (which is the atomic number) and also equal to the atomic number (since atomic number is the number of protons, and in neutral state, electrons = protons). So the blanks should be filled with "electrons", "protons", and "atomic number" respectively.

The electron configuration of aluminum (Al) is \(1s^2 2s^2 2p^6 3s^2 3p^1\). The principal quantum number (n) represents the energy level. Here, n = 1, 2, and 3 are present, so aluminum has electrons in 3 energy levels.

Answer:

1. electrons
2. protons
3. atomic number

Question 9