What trends can you see in the melting point and the boiling point of the halogens?

Melting and Boiling Points (increases down the group)

The melting and boiling points increase down the group because of the van der Waals forces. The size of the molecules increases down the group. This increase in size means an increase in the strength of the van der Waals forces.

Explanation:

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.

you did not give any options thus this is the best answer i can give to you with this little information you have given

> they are both natural and not man made

> they can be tracked and predicted by the right tools

-love shrooms