Radiation is s very powerful substance and can cause major health problems do the health care professionals limit the use to help not create sickness
They are called isotopes.
Example of isotopes are Hydrogen and deuterium.
Hydrogen is 1 proton and 0 neutrons.
Deuterium is 1 proton and 1 neutron
A. Sugar... Because the others are mixes of things and combinations. Sugar is pure and on its own.
I hope this helps!
