When was the element cymbal found in chemistry?

In 1961, Josso (, Sikran ( and Rahi (A) of the United States used a spiral accelerator to accelerate the bombardment of the Boron-11 ion with atomic number 5 to bombard the Californiun-252 isotope with atomic number 98, and when the two nuclei merged, a small amount of element 103 was produced, and the half-life of this nuclide was 8 seconds, and the energy was , which was the first discovery of element 103 lr. In honor of the creator of the spiral accelerator American physicist Lawrence (and named Lawrencium, the element symbol was first set as "lw", changed to "lr" in 1963, and the Chinese translation is "cymbal" (pronounced as labor). Birthium (lr) is the last member of the actinide series.

At present, there are 8 kinds of LR isotope meters that have been synthesized, with a mass of 253-260, all of which are radioactive. The longest life is 260lr with a half-life of less than 3 minutes, followed by 255lr and 256lr with half-lives of 22 seconds and 31 seconds, respectively.

In 1968, the Berkeley Laboratory studied the chemical behavior of element 103 in aqueous solution. In honor of Lawrence, the inventor of the cyclotron, element 103 was named "LW" (Lawrencium). In 1963 the element symbol was changed to LR.

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Resolution: Element name: Francium.

Atomic weight: [223].

Element Type: Metal.

Discovered by: Marguerite Perey Date of discovery: 1939.

Discovery: In 1939, it was discovered by French scientist Marguerite Perey in the product of actinide fission.

Element Description: Radioactive. Due to nuclear instability, 223FR has a maximum half-life of only 21 minutes. Its chemical properties can only be studied in trace ranges. It is the heaviest alkali metal element. Salts are all water-soluble.

Co-precipitation of francium with perchlorate, chloroplatinate, or tungsten silicate anions along with cesium support is an effective method for separating trace amounts of francium.

Elemental Aids:

Astatine and francium are iodine-like and cesium-like elements that Mosley determined as atomic numbers. Their discovery went through a winding path.

At first, chemists tried to find them from various salts based on Mendeleev's inference that iodine-like is a halogen and cesium-like is an alkali metal element, both of which form salts, but found nothing.

In July 1925, the British chemist Ferry Ender chose to go to the Dead Sea in the hot summer to look for them. However, after painstaking chemical analysis and spectroscopic analysis, none of these two elements were found.

Later, many chemists tried to use spectroscopy and atomic weight as a breakthrough to find this element, but they were unsuccessful.

In 1930, Alisheng, a professor of physics at the Alabama Institute of Technology, announced the discovery of element 87 by magneto-optical analysis in the rare alkali metal ore cesium and lepimomica. The element symbol is set to vi. A year later, he used the same method to discover element 85 in an extract from the action of aqua regia and monazite.

The element symbol is set to ab. Soon, however, magneto-optical analysis itself was denied, and the elements found with it were impossible.

By 1939, the French female scientist Piery discovered element 87 in the decay product of actinium's isotope 227ac and studied it. In honor of her homeland, element number 87 is called Francium, and the element symbol is FR.

It"? "Thallium"?

Thallium is a heavy metal element, ranked in the 6th period of the periodic table A group, English name: thallium, symbol TL, atomic number 81, relative atomic mass is. Melting point k, boiling point 1730 k.

It has a silvery-white metallic luster, which is quickly oxidized and darkened in the air at room temperature to become blue-gray, soft and soft, and the Mohs hardness is only.

All salts of thallium are highly toxic. Thallium is more toxic to humans than lead and mercury and is similar to arsenic.

Thallium was originally used in medicine and can be used externally for diseases such as tinea capitis. In modern medicine, the TL isotope thallium-201 is widely used as a radionuclear element in the detection and diagnosis of a variety of diseases.

Thallium is very important in the industry, and the alloy made of thallium has many characteristics such as improving the strength of the alloy, improving the hardness of the alloy, and enhancing the corrosion resistance of the alloy.

Thallium can also be used to make high-temperature superconducting materials.

Thallium metal. <>

The position of thallium in the periodic table.

119 species Since Mendeleev discovered the periodic law, people began to purposefully search for new chemical elements. Later, chemists believed that there were 92 natural elements in nature.

There are 116 species, and most of the heavy elements in the latter are synthetic elements.

Discovered in 1898 by Marie Curie and Pierre Curie in bituminous uranium mines, polonium was named polonium in honor of the motherland of Poland.