Which would result in radioactive decay? Check all that apply.

A) a neutron-to-proton ratio of 1:1 in a small nucleus

B) a neutron-to-proton ratio of 1:2 in a large nucleus

C) a nucleus that contains 90 protons and 100 neutrons

D) a nucleus that contains 8 protons and 8 neutrons

E) any isotope of the element uranium, which has atomic number 92

F) any isotope of the element potassium, which has atomic number 19