Changing the wavelength of the carrier wave to match that of the signal is called
a. amplitude modulation.
b. crest modulation.
c. frequency modulation.
d. trough modulation.

Why does a plastic bottle that is sealed at a high altitude change it’s shape when taken to lower altitude

For either problem would be greatly appreciated

One of the few xenon compounds that form is cesium xenon heptafluoride (csxef7). how many moles of csxef7 can be produced from the reaction of 14.0 mol cesium fluoride with 14.0 mol xenon hexafluoride? csf(s) + xef6(s) csxef7(s)