How do atoms achieve stability in single covalent bonds?
Atoms achieve stability in a single covalent bond by sharing valence electrons to create filled electron shells which are stable.
"Co-" means to share. Valence electrons are the outermost electrons in an atom. By sharing the valence electrons, atoms can achieve a filled valence shell which is stable.
- Neon has eight valence electrons in its outer shell. Neon is a very stable atom. Neon is part of family called the Noble gases because of their stability these atoms rarely interact with other atoms.
- Oxygen has six valence electrons in its outer shell. Eight electrons are needed to fill the second level to achieve stability. So oxygen needs two more electrons to be stable.
- Hydrogen has one electron in its outer shell, so two electrons are all that are needed in the first period (see helium, number two, a noble gas). Hydrogen needs one more electron to be stable.
- Two hydrogen atoms each share their electron with oxygen, giving oxygen a total of eight electrons, creating a filled shell for oxygen.
The oxygen in turn shares one of its valence electrons with each of the two hydrogens in
#\mathbf("H"_2"O")#(water), providing each hydrogen with a filled shell. By sharing all the atoms are filled and "happy", like neon and helium.