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

Explanation:

1. Analyze each option:

• Option 1: A half - life is the time it takes for half of the radioactive atoms in a sample to decay. So elements with a half - life are radioactive and undergo radioactive decay.
• Option 2: All atoms (of any element) contain protons, but not all elements with protons undergo radioactive decay (e.g., stable isotopes of carbon like C - 12).
• Option 3: Elements that have turned into a new element are the result of radioactive decay, not the ones undergoing it.
• Option 4: Elements with a consistent number of particles are stable and do not undergo radioactive decay as radioactive decay involves a change in the number of particles (like emission of alpha, beta, or gamma particles).

Answer:

A. all elements that have a half - life