1) rank the elements, aluminum, sodium and phosphorus, in order of decreasing conductivity. 2) rank the elements aluminum, gallium, and boron in order of decreasing conductivity

Conductivity is the ability of a substance to allow charge or electricity to pass through it. Metals have a lot of free electrons and are considered as good conductors while non-metals do not conduct electricity

1) In the given examples:

Al is a metal, Na is an alkali metal while P is a non-metal

The decreasing order of conductivity would be:

Al > Na > P

2)

Both Al and Ga are metals while B is metalloid.

Among Al and Ga, Al is a solid at room temperature and a better conductor of electricity. hence the decreasing order would be:

Al > Ga > B