What are signs that a chemical reaction has occured

Fission of uranium-235 products energy and a. isotopes of smaller elements b. isotopes of larger elements c. lighter isotopes of uranium d. heavier isotopes of uranium

What is the mass defect of a mole of nuclei with 1.8 x 10^15 j/mol binding energy?

Ants live on acacia trees in south america. the ants feed on sugars secreted by the trees. the trees provide room for the ants to live. the ants sting any other insect or animal that comes to eat the trees. what type of relationship is this?