1) Rank the elements, aluminum, sodium and phosphorus, in order of decreasing conductivity.

Question

2) Rank the elements aluminum, gallium, and boron in order of decreasing conductivity

Answer 1

Here is a table of resistivity. Resistivity is the reciprocal of conductivity, the higher the resistivity, the lower the conductivity.

http://www.webelements.com/periodicity/electrical_resistivity/