I think the correct answer from the choices listed above is option A. The key characteristic by which Dmitri Mendeleev arranged his periodic table was that the elements are arranged in increasing atomic number. Hope this answers the question.
I believe the answer is orbital hybridization theory
Simple,
take a look at your periodic table, if you have it labeled look at the Halogen
Group, it includes: Flourine, Chlorine, Bromine, Iodine, and Astatine.
Now, a period on the periodic table is read from left to right, and goes
down the rows of the periodic table.
Go to Period 5, go all the way to the Halogens, what is there?
Iodine.
Thus, your answer.
the liquid will expand from the heat, and the mercury in the thermometer will rise or fall (depending if it is warming up or cooling).