GEOLOGY

Detailed explanation-1: -Let me begin by pointing out that the half-life of 238U is about 4.5 billion years. That means that if you have two atoms of 238U, each of them has a 50% chance of decaying in the next 4.5 billion years.

Detailed explanation-2: -Plutonium-239 (a manmade isotope) has a half-life of 24, 000 years.

Detailed explanation-3: -This rate is known as a half-life; the amount of time it takes for approximately half of the radioactive atoms in a sample to decay into a more stable form. The image above indicates that radium-226 has a half-life of 1, 602 years.

Detailed explanation-4: -The half-life of a radioactive isotope is the amount of time it takes for one-half of the radioactive isotope to decay. The half-life of a specific radioactive isotope is constant; it is unaffected by conditions and is independent of the initial amount of that isotope.