What’s the key point in this What does this mean???

rubbing two solids together often results in static charge so there must be something (electrons) on the outsides of atoms which can be transferred as atoms collide

po-215 i got it right on the quiz

every chemical equation adheres to the law of conservation of mass, which states that matter cannot be created or destroyed. therefore, there must be the same number of atoms of each element on each side of a chemical equation.

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.