I think you mean filled electron LEVELS. An atom is made up of two parts: 1) a nucleus composed of protons and neutrons, and 2) levels of electrons surrounding the nucleus (called energy levels). Each energy level can hold a certain maximum number of electrons.
The outermost energy level can hold 8 electrons max. These electrons are called 'valence electrons'. It is every atom's "desire" to achieve 8 valence electrons. However, some atoms do not have 8 valence electrons, so they bond (or share electrons) with other atoms so each atom can achieve a filled valence electron level (8 electrons). (NOTE: When two atoms have bonded to achieve 8 electrons, the atoms are now called IONS).
Filled electron levels are significant because:
*In an atom, electrons must fill each energy level up completely before electrons can occupy the next level.
*Filled electron levels allow atoms to bond with each other, creating ions.
I hope that helps you out :)
The outermost energy level can hold 8 electrons max. These electrons are called 'valence electrons'. It is every atom's "desire" to achieve 8 valence electrons. However, some atoms do not have 8 valence electrons, so they bond (or share electrons) with other atoms so each atom can achieve a filled valence electron level (8 electrons). (NOTE: When two atoms have bonded to achieve 8 electrons, the atoms are now called IONS).
Filled electron levels are significant because:
*In an atom, electrons must fill each energy level up completely before electrons can occupy the next level.
*Filled electron levels allow atoms to bond with each other, creating ions.
I hope that helps you out :)