Question

Which material undergoes radioactive decay?

all elements that have a half-life
all elements that contain atoms with protons
all elements that have turned into a new element
all elements that have a consistent number of particles

Answer 1

all elements that have a half-life

Explanation: Radioactive decay occurs in unstable nuclides (isotopes) that have a measurable half-life. Stable nuclides do not undergo radioactive decay.