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How can I count valence electrons?

Answer 1

Ellie Andrews

The electrons that define an element's most common bonding patterns are called valence electrons.

These electrons are located in the element's highest energy level's s and p orbitals.

Sodium #1s^2 2s^2 2p^6 3s^1# Sodium has 1 valence electron from the 3s orbital

There are five valence electrons in phosphorus: two from the 3s and three from the 3p.

Iron #1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^6# Iron has 2 valence electrons from the 4s

Bromine #1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^10 4p^5# Bromine has 7 valence electrons 2 from the 4s and 5 from the 4p you can count the electrons in the out most shell

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Answer 2

Wyatt Adkins

Using the periodic table, you can find out how many valence electrons an atom has: for main group elements, it equals the group number; for transition metals, it equals the number of electrons in the outermost shell; and for ions, it equals the charge of the ion.

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.