What do all group 2 elements have in common? they all gain two electrons to form a stable outer energy level. they form covalent bonds with halogens. they all react easily with the noble gases. they tend to form ionic bonds by losing electrons

Two models of the same compound are shown. in what way is model b better than model a? model b shows the types of elements in the compound, but model a does not. model b shows the three-dimensional shape of the molecule, but model a does not. model b shows how the atoms in the molecule are connected, but model a does not. model b shows the number of atoms of each element in the molecule, but model a does not