Question

How does the following property vary on moving down group 17?

Density

Answer 1

1. Density increases as we move down group 17 elements (halogens).
2. This happens due to an increase in atomic mass and size on moving down the group.
3. The state of agglomeration (from gas to solid) also increases down the group, increasing density.
4. Stronger van der Waals forces between larger atoms cause molecules to pack more closely.
5. Therefore, fluorine has the lowest density and astatine the highest in the group.