1. How many moles of tin are needed to react with 3.5 moles of hydrogen fluoride?

If anyone would be able to me out with these three questions it would be these are from the chem 2202 course.

Which element is least likely to undergo a chemical reaction

Phosphorous can form an ion called phosphide, which has the formula p3−. this ion can form an ion called phosphide, which has the formula p3−. this ion properties very similar to those of pforms when a phosphorus atom loses three protonsis called a cationcontains 18 electrons