Number 19 is frequency and not sure which question you asked!!!??
The radiations detected by Arno Penzias and Robert Wilson
were the original heat from the Big Bang.
Today, we call those waves the "Cosmic Microwave Background".
I'm not sure, but I think those guys were awarded a Nobel Prize in Physics
for that discovery.
Potential energy is stored energy. For example, if a bowling ball is on top of a giant hill, we say it has potential energy because it has the potential to do work which is to roll down the hill.
Kinetic energy is the energy of movement so once that ball rolls down that hill, that potential energy is converted to kinetic energy.
Your not really supposed to date your relative