How Do You Find Number of Valence Electrons?

[penguins]

Can you tell me how to get number of valence electrons?Im in 8th Grade can you tell me in small words im not that stupid though but can you tell me how to tell it step by step.I need to find Number of Valence Electrons of Aluminum tell me what the Valence electron and how to do it.

[sammy]

Valence electrons are the electrons in the shell furthest from the nucleus(the last shell). Aluminum has 13 protons. Two protons fill the first shell, eight fill the second shell, and three fill the last one. That uses up all 13 protons. Aluminum has 3 valence electrons(the 3 electrons in the final shell).

Keep in mind you can only put two protons in the first shell, and eight in the other shells.

[april345]

Periodic Table
For non-transition metals the group that it's in = the number of valence electrons

For transition metals you need to remember the common ones.

As Al is non a transition metal it has 3 valence electrons

[RYAN BANYAN]

The "magic" numbers are 2, 8, 18, 32, 32, 18, 8 and so on.

In science, valence electrons are the outermost electrons of an atom, which are important in determining how the atom reacts chemically with other atoms.

The number of valence electrons of an element is determined by its periodic table group (vertical column) in which the element is categorized.