To understand uranium, it is very important to understand radioactivity. Uranium has natural radioactivity: its nucleus is unstable, so the elements are in a state of constant decay, seeking a more stable arrangement. In fact, uranium is the element that makes the discovery of radioactivity possible. 1897, French physicist henry beck Rael left some uranium salts on the photographic plate as part of studying how light affects these salts. To his surprise, there was fog on the board, which indicated that the uranium salt had some discharge. 1903, becquerel won the Nobel Prize with Mary and pierre curie for this discovery. According to the research of Jefferson National Linear Accelerator Laboratory,
The fact is that the nature of uranium is:
Atomic number of uranium (Andrei Marincas Shutterstock): 92 atomic symbol (on the periodic table of elements): U atomic weight (average atomic mass): 238.09 1 density: 18.95g per cubic centimeter at room temperature; phase: solid melting point: 2075 degrees Fahrenheit (18). 8 degrees Fahrenheit (4 13 1 celsius) isotope number (atoms of the same element have different neutron numbers): 16. The three most common natural isotopes are uranium 234 (natural abundance is 0.0054%) and uranium 235 (natural abundance is 0.7204%). The uranium -K8(99.2742% natural abundance) history of German chemist Martin Heinrich Klaproth discovered uranium in 1789, although according to chemical engineers, uranium oxide was known at least in 79 AD, when it was used as a colorant for ceramic glazes and glasses. Klapp Lott discovered elements in pitchblende, which were thought to be zinc and iron ore at that time. Dissolve minerals in nitric acid, and then add potassium (potassium salt) to the remaining yellow precipitate. Klapp Lott concluded that he discovered a new element when the reaction between potassium salt and precipitate did not follow the reaction of any known element. His discovery turned out to be uranium oxide, not pure uranium as he thought. According to Los Alamos National Laboratory, "KDSP" and "KDSP" were named as newly discovered elements. This is the recently discovered Uranus, which is named after the Greek god of the sky. 184 1 year, French chemist Eugene melchior pelligott heated uranium tetrachloride with potassium to separate pure uranium. 1896, French physicist Antoine H. Becker discovered that uranium is radioactive. Becquerel left uranium samples on unexposed photographic negatives, which became turbid. According to the Royal Chemical Society, he came to the conclusion that it emits invisible light. This is the first time that radioactive research has opened up a new scientific field. Marie Curie, a Polish scientist, coined the word "radioactivity" shortly after she discovered radioactive elements in becquerel, and continued her research with pierre curie, a French scientist, and discovered other radioactive elements, such as polonium and radium. According to the data of the World Nuclear Association, uranium in the universe was formed in a supernova 6.6 billion years ago. It is all over the earth, accounting for about two to four parts per million in most rocks. It ranks 48th among the richest elements. Uranyl compounds in high temperature glass make it release photons when it sinks. Solid uranium oxide. This is the form in which uranium is usually sold before enrichment. According to the data of the World Nuclear Association, uranium is mined in 20 countries, more than half of which come from Canada, Kazakhstan, Australia, Niger, Russia and Namibia. Rentek believes that all humans and animals will naturally come into contact with trace uranium in food, water, soil and air. In most cases, ordinary people can safely ignore their intake unless they live near dangerous garbage dumps and mines, or crops grow in polluted soil or are watered with polluted water. in view of
The importance of uranium in nuclear fuel, researchers are very interested in the function of uranium, especially during meltdown. When the cooling system around the reactor fails and the heat generated by the fission reaction in the reactor core melts the fuel, meltdown will occur. This happened during the nuclear disaster at the Chernobyl nuclear power plant, which led to a radioactive substance called elephant foot.
It is very important for nuclear engineers to understand the behavior of nuclear fuel when it melts. John Paris said that in 20 14 1 1 year, Paris and colleagues from Argonne National Laboratory published a paper in Science, which clarified the internal working principle of molten uranium dioxide, the main component of nuclear fuel, for the first time. Parise told LiveScience that uranium dioxide won't melt until the temperature reaches 5,432 degrees Fahrenheit (3,000 degrees Celsius), so it's difficult to measure what happens when a substance becomes a liquid-there is no container that is strong enough. Our solution is to heat the uranium dioxide ball from the top with a carbon dioxide laser. "The ball floats on the air," said Paris. You have a ball of matter floating on the airflow, so you don't need a container. "kdspe" and "kdsps", and then the researchers let x-rays pass through uranium dioxide bubbles and measure the scattering of x-rays with detectors. The scattering angle reveals the internal atomic structure of uranium dioxide. KD SPE "KD SPS". The researchers found that in solid uranium dioxide, atoms are arranged in a series of cubes, alternately arranged in a grid pattern, and there are 8 oxygen atoms around each uranium atom. Lawrie Skinner, a researcher at Argonne National Laboratory, said in a video about the experimental results that when this substance is close to the melting point, oxygen will become "crazy". Oxygen atoms began to move around and filled the space, jumping from one uranium atom to another.
Finally, when the material melts, the structure is like salvador dali's painting, and the cube becomes a disordered polyhedron. At this point, Paris said, the number of oxygen atoms around each uranium atom (called coordination number) has been reduced from eight to about seven (some uranium atoms have six oxygen atoms around them, while others have seven, Paris said, "The average number of oxygen atoms per uranium is 6.7." Kdspe "kdsps" knows this number, which makes it possible to model the behavior of uranium dioxide at high temperature. The next step is to add more complexity. He said that the nucleus is not just uranium dioxide. They also include zirconium and any materials used to protect the reactor interior. The research team now plans to add these materials to see how the reaction of the materials changes. You need to know the behavior of pure uranium dioxide liquid, so that when you start to observe the influence of a small amount of additives, can you see the difference between them? Paris said:
The vast majority of uranium is used to generate electricity, usually to control nuclear reactions. The remaining depleted uranium can be recovered and used for other types of energy, such as solar energy. 20 17 patent of Igor Usov and Milan secor.