If there's a jar that contains helium gas . what would happen if the lid of the jar was removed ?

What is the percent by mass of oxygen in fe2o3

Imagine that you push on a large rock. at what point does your effort change the rock’s mechanical energy?

The characteristics of two different types of reactions are shown below: reaction a: electrons are gained by the atoms of an element. reaction b: protons are lost by the atom of an element. which statement is true about the atoms of the elements that participate in the two reactions? their identity changes in both reaction a and reaction b. their identity changes in reaction a but not in reaction b. their identity changes in reaction b but not in reaction a. their identity remains the same in both reaction a and reaction b.