Author: Tyler Vazquez
Editor: Tharindi Jayatilake
Artist: Tiffany Chen
Uranium is the 92nd element located on the Periodic Table of the Elements. With an abundance of about 4 parts per million in the Earth’s crust, it is both a rare and powerful element. As an actinide, it is both synthetically and naturally produced. Let's take a glance into this unique element that has quite possibly changed the world.
Uranium has no stable isotopes. This means that each of its radioisotopes must decay, emitting radiation in order to revert to stability. Uranium often decays via alpha emission, though gamma emission is known as well. Alpha ray emission means that an atom of uranium will release 2 protons and 2 neutrons at any point in time. This alpha particle is quite similar to that of the mass, structure, and function of a helium atom, despite carrying no electrons like that of helium. Two of uranium’s most common radioisotopes include Uranium-235 and Uranium-238, though others, such as Uranium -233, exist. Uranium is theorized to have formed in supernovae and stars throughout the universe about 6.6 billion years ago.
According to the Center for Disease Control, Uranium-235 has a half-life of about 700 million years, while Uranium-238 has a half-life of about 4.47 billion years. This means that for a sample of both isotopes of uranium, it would take nearly 1 billion and 4.5 billion years respectively for half of the atoms in the sample to emit alpha particles.
Since it is nearly impossible to calculate when one particular atom emits radiation, this half-life method is quite common. The heaviest isotope’s half-life is only slightly shorter than the age of the Earth, making it a useful isotope to determine the age of rocks and minerals. Uranium-238 eventually forms intermediate radioactive particles such as Uranium-234 and Thorium-230 before eventually reaching the end of a decay series when it reaches stability as an isotope of lead.
As a heavy, unstable metal, uranium is quite harmful to the human body. Although trace amounts of the element can be discovered in the air, groundwater, and plants, ingesting uranium over long periods of time is linked to the development of bone and liver cancers. The alpha particles are emitted throughout the body, which is incredibly lethal for cells, often resulting in apoptosis or cell degeneration as well.
Uranium has the appearance of a silvery, thin sheet of metal, and as an industrial element, it is often bound to oxygen in triuranium octoxide, a common compound found in yellowcake mixtures. Yellowcake is essential in being a reactant with several compounds that effectively and efficiently form uranium-powered fuel for nuclear reactors throughout the world. Uranium is often considered enriched and most useful when there is a high concentration of it in a given sample.
Discovered in 1789 by German chemist Martin Klaproth, uranium has since been a major industrial and weaponry compound, from creating the first known atomic bombs to the utilization of nuclear energy. Australia currently contains 30% of the world’s uranium supplies, with Kazakhstan following at 14%. However, Kazakhstan also currently mines more uranium than any other country in the world. Despite its harmful effects on life, this element has been at the forefront of international discussions, from politics to physics to chemistry to environmental protection.
Agency for Toxic Substances and Disease Registry. “Uranium (U) Toxicity: What Is Uranium
ATSDR - Environmental Medicine & Environmental Health Education - CSEM.”
ATSDR, 2009, www.atsdr.cdc.gov/csem/csem.asp?csem=16&po=4.
“CDC Radiation Emergencies | Radioisotope Brief: Uranium-235 (U-235) and Uranium-238
(U-238.” Center for Disease Control and Prevention,www.cdc.gov/nceh/radiation
/emergencies/isotopes/uranium.htm. Accessed 19 Oct. 2020.
“Uranium.” UC Berkeley, University of California, Berkeley, nature.berkeley.edu/classes/eps2/wisc/u.html#:%7E:text=The%20overall%20abundance
“What Is Uranium? How Does It Work - World Nuclear Association.” World Nuclear
cycle/introduction/what-is-uranium-how-does-it-work.aspx. Accessed 19 Oct. 2020.