C. The number of covalent bonds is equal to the number of unpaired valence electrons. For example, nitrogen and phosphorous both have 3 unpaired valence electrons thus forming 3 covalent bonds.
D. Infrared images can show hot spots as red areas.
Groundwater is defined as water that is found beneath the surface of the earth in conditions of 100 percent saturation (if is less than 100 percent saturation,then the water is considered soil moisture).Ninety-eight percent of earth’s available fresh water is groundwater
<span>it is described as an inversion heterozygote</span>