Electrons are in regions around the nucleus that are different distances away from the nucleus. The electrons surround the nucleus in 3 dimensions but it is easier to show an energy level model in two ...

When two hydrogen atoms get close enough, the electron from each atom feels an attraction from the proton in the other atom's nucleus. This attraction pulls the atoms together. The electrons end up ...

and atoms of group 2 elements have two electrons in their outer shell. Elements in groups 6, 7 and 0 are non-metals. Atoms of group 7 elements have seven electrons in their outer shell ...

If the imbalance is too great, radioactive decay will occur. Up to two electrons may exist in the atom's first shell. Up to eight electrons may exist in the atom's second shell. An electron may ...

A helium atom has two electrons in an energy level outside the nucleus. The atom is neutral as it has two positive protons and two negative electrons. A helium atom that has lost or gained an ...