a reaction where particular set of chemicals changes into another form without changing their nuclei just the transfer or sharing of electrons and formation and breaking of bonds is called as chemical reaction.
example- formation of water, photosynthesis etc.
but if there is a change in nuclei than it would be called as nuclear reaction.
like Uranium breakdown etc.
Darwins proposed theory is the survival of the fittest.
Answer:
c) matter in an ecosystem flows in one direction and is never reused.
Explanation:
A is true
