what is electromagnetic radiation?
a) the transfer of energy as sound waves
'Wave' is a common term for a number of different ways in which energy is transferred: In electromagnetic waves, energy is transferred through vibrations of electric and magnetic fields. In sound waves, energy is transferred through vibration of air particles or particles of a solid through which the sound travels.
Explanation is in a file
your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.