There are five basic Hardy-Weinberg assumptions: no mutation, random mating, no gene flow, infinite population size, and no selection. If the assumptions are not met for a gene, the population may evolve for that gene (the gene's allele frequencies may change).
Hydrogen has 1 Valence electron, and H2O has 2 Hydrogen. Oxygen has 6 Valence electrons so do 2+6 = 8. 8 Valence electrons! (Or one full shell not consisting of the first shell.)