Answer:
Even in a chemical reaction when atoms interact and create new products, mass is conserved. This is because the new substances created are composed of atoms that were present in the reactants. The atoms from the reactants come apart, rearrange, and re-bond in a different arrangement to form the products.
Answer:
activation energy is required for a chemical reaction to take place.
Extinction is a natural process that may be caused by natural selection, shortage of food or natural calamities. Hunting, deforestation, pollution, the conversion of uncultivated areas into pastures, the illicit trade of wild animals as well as climatic changes have made life more difficult for many animals.