The time for half the atoms in a radioactive substance to disintegrate
https://www.vocabulary.com/dictionary/half-life
Potential energy is highest at the top of the loop, and kinetic energy is highest at the bottom of the loop.
Answer:
Visible Light and Radio waves
Explanation:
The earth's atmosphere is transparent to a few windows in the electromagnetic spectrum. it is completely transparent to allow observation from the ground in visible light rang 380 to 740 nano meters. Also in the range of radio wave as communication are done from space to ground in the form of radio waves.
it is Partially transparent to Microwave and infrared range.
I think its between b or c
Infra-red has wavelengths just longer than visible light.
