15. D is correct, exothermic reactions release heat
I am not sure about 16
Answer:
transmutation, conversion of one chemical element into another. A transmutation entails a change in the structure of atomic nuclei and hence may be induced by a nuclear reaction (q.v.), such as neutron capture, or occur spontaneously by radioactive decay, such as alpha decay and beta decay .
Gold, as it has the unique characteristic yo
Answer:
The oeriodic table have 8 groups
