The Alkali Metals- (Group 1A)can be found (excluding hydrogen) in the first column of the periodic table. They all have 1 valence electron and tend to form +1 cations when forming Ionic bonds with non metals.
The Alkali Earth Metals: (Group 2A) can be found in the second column/group on the periodic table. These elements form +2 positively charged cations when forming Ionic bonds with non metals. They also all have 2 valence electrons.
The Halogens: are the elements that make up the second to last group on the periodic table. These elements include Chlorine, Fluorine, Bromine, Iodine, and Astatine. These elements have 7 valence electrons. The usually form a -1 charged anion when forming ionic bonds with metals.
The Noble gases: the very last group on the periodic table. All these elements have 8 valance electrons. Due to the octet rule these atoms are already very stable and rarely react with other elements.
The volume and the density of the substance depend on inter molecular forces of the substance. So, when we will change the degree of inter molecular forces, whether decrease it or increase it, it will affect the volume and density of a substance.
