Using the periodic table, determine which material is most likely to be a good insulator. magnesium silver aluminum sulfur

Idon’t understand this page, can someone ?

Why doesn't heat added to water make the tempature rise above 100c

Water undergoes a large change in density at 0 ∘ c as it freezes to form ice. calculate the percent change in density that occurs when liquid water freezes to ice at 0 ∘ c given that