When storm clouds produce lightning and thunder, energy changes to energy and energy. when storm clouds produce lightning and thunder, energy changes to energy and energy.

Electric potential energy to radiant energy and sound energy.

Explanation:

At the time of lightning, it is known that the clouds are at high electric potential and the surface of the Earth is at low potential. Because of this potential difference, the particles of the charge in the atmosphere possesses the capability to mediate from high potential to low potential.  

At the same time, the presence of moisture and certain dipole gases in the atmosphere will possess the capability to show dissociation and because of this dissociation and movement of charge, the process of lightening takes place. Thus, here the electric potential energy of the charged particles will get modify and it will get transformed into sound energy, as it generates sound as well as the radiant energy at the same time in the form of lightning.  

a sperm cell fertilizes an egg cell.

the answer is d. chordata