Explain some trends when going down Group 7 of Halogens in the Periodic Table

Going down Group 7 in the period table, the mass number increases, so the element becomes heavier. The period increases so the number of shells increase, though they all still require one electron to fill its outer shell. The melting points and boiling points of the halogens increase as you go down the group. This is because larger molecules within the same group experience greater intermolecular interactions with each-other, & more energy is required to overcome the interactions between neighbouring atoms. Going down the group, the state of the elements changes from gas to liquid to solid, to indicate the change in melting and boiling points as you go down the group.