it is a large part of what determines its chemical properties. Atoms that have 1, 2, or 3 valence electrons tend to lose those electrons. They also tend to be metallic (except for hydrogen, whose metallic properties only emerge under very low temperatures and high pressures). Atoms with 5, 6, or 7 valence electrons are often nonmetals or metalloids. They tend to gain more electrons until they have 8 valence electrons, either by taking them from atoms with fewer valence electrons or by sharing with other nonmetals. Atoms with 4 valence electrons include metals, nonmetals, and metalloids, they often lose, gain, or share valence electrons depending on how far they are down the periodic table and what they're bonding with. And atoms with 8 valence electrons (or 2 in the case of helium) don't lose, gain, or share electrons under normal conditions. They are called noble gases.