Answer:
3 valence electrons
Explanation:
Because aluminum has three, that means three fluorines can bond. The make the formula AlF3, also known as aluminum trifluoride. Each of the fluorine atoms gets an electron to fill their shell, and the aluminum loses three, giving it a filled shell too (remember, aluminum has three extra electrons).
2nd group of the periodic table
When other scientists repeat experiments and come up with the same results it validates it and show that the answers are true
