Brian is riding his skateboard to his friend's house. brian is pushing on the ground with his foot to move himself and the skateboard forward. which energy is transformed into mechanical energy?
a. radiant energy
b. chemical energy
c. sound energy
d. electrical energy

The law of conservation of energy says energy cannot be created or destroyed, so the answer is Chemical energy

in 1783 cavendish was working with his hydrogen gas and found that when he burned it and condensed the vapor it was water. this was very significant since it disproved the greek theory of elements completely since water was not a simple substance but the product of two gases. it was lavoisier who hearing of the experiment gave cavendish's gas the name hydrogen ("water-producer") and added that hydrogen burned by combining with oxygen and that water was a hydrogen-oxygen combination.

explanation: