The atomic number tells us the number of protons and electrons. The atomic mass tells us the weight of the nucleus, which is the amount of protons and neutrons
When you walk your dog, you are using energy from the sunlight to power the activity. Explain. The energy you use is transferred from glucose, which got it directly from sunlight.
Covalent compounds have low forces of attraction between their molecules (i.e. one H2O molecule isn't as attracted to another H2O molecule than the oppositely charges ions are in an ionic compound). Little energy is needed to break their bonds, therefore they have low meting points. Hope this is what you are looking for!
