What element has the lowest density of all elements

Hydrogen has the lowest density because it has a density of 0.09. All other elements have a density about 1, which means that Hydrogen is the least dense of all of them.

I am so sorry that I could not give a more detailed exclamation. ;-;

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.