The positive and negative ions attract each other and form the ionic compound sodium chloride. One calcium and two chlorine atoms are near each other. An electron from each atom feels the attraction ...

If the compound contains three elements one of which is oxygen then the compound name will end in –ate or –ite, eg Calcium carbonate ... contains one carbon atom joined to one oxygen atom ...

Players read questions about energy levels and score points by picking the correct element as the answer. Electrons are in regions around the nucleus ... electrons on the first energy level and six ...

Atoms of different elements usually have different ... the mass number of argon atoms and calcium atoms can both be 40. The atomic number of a chlorine atom is 17 and its mass number is 35.