Me urgent!

you place a balloon in a closed chamber at standard temperature and pressure (stp). you cool the chamber to half of its original temperature while leaving the pressure constant. what happens to the balloon?
it stays the same volume.

it decreases to one-half of its original volume.

it doubles in volume.

it expands to four times its original volume.

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.