The correct answer is
b. low frequencies and low energy.
In fact, microwaves and radio waves have frequency up to 
, which are really low compared, for instance, to the frequency of gamma rays (
). Moreover, the energy of an electromagnetic wave is directly proportional to its frequency:
where h is the Planck constant and f the frequency; therefore, low frequency means also low energy.
<span>These are isotopes of carbon and they all contain 6 protons and 6 electrons but each contains a difference number of neutrons - 6, 7, and 8 respectively.
^ This is the answer because an isotope changes the atomic mass, NOT atomic number. That means that the neutrons are changed, not the protons. </span>
Energy from the sun is referred to as solar energy.
So energy from the sun is solar energy.
hope it helps!!!
