and nitrogen. You may want each group to create a color key they can refer to in order to remember the color that represents each atom. If you cannot get Snap Cubes, you can use colored Styrofoam ...

The formula is H 2 O so the dot and cross diagram includes two H atoms and one O atom. H has 1 outer electron. O has 6 outer electrons. The H circles must each overlap the O circle. Nitrogen ...