Valence Electrons

Eight is Great

Valence Electrons

Are the outermost electrons on an atom Are in the outermost energy level Are the electrons that are lost or gained

to form ions

Stable Configuration

Atoms are most stable with 8 valence electrons (except H and He like 2 valence electrons)

Atoms will gain or lose electrons to achieve this stable condition (configuration)

Atoms will bond to achieve this configuration

Complete valence shell

A complete valence shell has 8 electrons H and He have 2 electrons H can have no electrons

The next lowest row has a complete valence shell

Metals

If an atom has one valence electron… It could lose 1 or gain 7 electrons It loses one negative electron…

Becoming more positive

Non-metals

If an atom has seven valence electrons… It could lose 7 or gain 1 electron It gains one negative electron…

Becoming more negative

Flame Test Notes

Ground State - the lowest energy state of an electron

The most stable state for each electron Takes the least amount of energy

Important Information to the Lab If an electron acquires additional energy

it becomes excited and moves into a higher energy state.

It will fall quickly back to the ground state while emitting a PHOTON of light

The amount of energy associated with the photon results in the different colors of light being emitted.

Excited State

The condition of an atom in a higher energy state than a ground state

Must put energy into the atom (heat) Same amount of energy is released as

light energy (quanta)