Radioactive substances emit ionizing energy during decay, with alpha, beta, and gamma radiation being the most common. The level of radioactivity depends on the type of radiation and how easily it can be shielded. Half-life is a useful measure for determining the most radioactive substances, with elements at the end of the periodic table being the most radioactive. Plutonium-239, often considered the most radioactive substance on earth, is actually less radioactive than recently created elements such as ununpentium.
A radioactive substance is a substance that is undergoing radioactive decay. This is when the nucleus of the atom is unstable, and therefore gives off ionizing energy. This causes it to reach a lower energy state and transform.
The idea of which substance is more radioactive is somewhat problematic in and of itself, because we have to ask what we really mean by more radioactive. There are three main types of ionizing radiation: alpha, beta and gamma. These are named after the various particles that a radioactive substance can emit. An alpha particle consists of two protons bonded together with two neutrons to form something that is equal to the nucleus of helium. A beta particle is a positron or an electron. And gamma rays are high-energy protons, with energy above the 100 keV range. There are other types of radiation as well, but these three make up the majority of observable radiation.
The dangers of these forms of radiation, which play into how we think about which element is the most radioactive, are in many ways influenced by how easily they are shielded. Alpha particles, for example, will bounce off just about anything, even a thin sheet of paper or your skin. Beta rays penetrate the most basic shielding, but can be stopped by something like aluminum. Gamma rays, on the other hand, penetrate almost everything, which is why heavy lead shielding is often used in situations where gamma rays can be released.
As a radioactive element transforms, it can undergo various forms of decay along the way. For example, uranium-238 releases an alpha particle to transform into thorium-234, which in turn releases a beta particle to transform into protactinium-234. So a single substance can actually turn into many different radioactive substances during its life cycle and can release different types of radioactive energy in the process.
Perhaps the easiest way to gauge which substance is the most radioactive is to look at the half-lives. An element’s half-life is the time it takes for the element to decay to half its original size. Elements with extremely long half-lives can actually appear stable, because they take a long time to release energy in the form of radioactive decay. These long-lived elements, like bismuth, for example, can be treated as essentially non-radioactive, and thus are far from being the most radioactive. Likewise, elements like radium have half-lives well in excess of 500 years, and thus aren’t even in contention to be the most radioactive.
Elements like promethium, on the other hand, are dangerous enough not to be handled safely, but not anywhere near the most radioactive. As you move further down the periodic table, you start to find more and more radioactive substances, such as nobelium and lawrentium. These have half-lives in the minutes and are quite radioactive.
However, to find the most radioactive substances we have to go to the ends of the periodic table, to never-before-seen elements only after they were created by man. Elements such as unbibium at the end of the table, or ununpentium, are among the most radioactive known to man. Ununpentium-287, for example, has a half-life of only 32ms. This can be compared to elements such as plutonium-239, which has a half-life of over 200 years and therefore, while quite toxic, is nowhere near as radioactive as the heavier elements. While often called the most radioactive substance on earth, plutonium is actually quite tame compared to the only recently created ununpentium, ununtrium, ununoctium, and many others.
Protect your devices with Threat Protection by NordVPN
