Use the triboelectric series to determine which of the following materials will develop a positive charge when rubbed with wool. aluminum can paper cup pvc pipe glass jar

Option (d) is the correct charge.

Explanation:

Triboelectric series help us to determine the charge of an object when it is rubbed against an object of known charge.

Therefore, according to this series when wool is rubbed with a glass jar then it will acquire a positive jar.

Whereas aluminium can and paper cup will be very less positively charged when rubbed with wool.

it's filtration, but this is an assumption so my apologies if i got this

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.