Which statement best describes what happens in a fission reaction

The answer is; Heavy nuclei split into lighter nuclei

Heavier isotopes of elements are the most unstable and decay quickly into lighter elements (mostly because they have  high neutron to proton ratio). The decay involves the splitting of the heavier atom into a lighter atom and the release of neutron(s) particles and radiation energy. The released neutrons then hit another isotope and split it. This chain of reaction continues so far as the isotopes are close by. The time it takes for a radioactive element to decay into another element is called half-life.

a. the law of proportion states the combination of 2 atoms in a specific ratio to produce multiple compounds such as the given statement of question ‘1st compound contains 88.8 % cu ’ indicates 88.8 g of cu is present along with 11.2 g oxygen in 100 g of compound whereas the statement ‘2st compound contains 79.9 % cu ’ indicates 79.9 g of cu is present along with 20.1 g oxygen in 100 g of compound

1st compound contains 88.8 g cu

for cu

m = 63 g /mol

atomic % = 88.8 /63 = 1.42

for o

m = 16 g /mol

atomic % = 11.2 /16 = 0.7

b. the emperical formula of 1st compound is

cu1.4o0.7

cu2o