Radium bromide is the bromide

Bromide

A bromide is a chemical compound containing bromide ion, that is bromine atom with effective charge of −1. The class name can include ionic compounds such as caesium bromide or covalent compounds such as sulfur dibromide.-Natural occurrence:...

 salt

Salt

In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...

 of radium

Radium

Radium is a chemical element with atomic number 88, represented by the symbol Ra. Radium is an almost pure-white alkaline earth metal, but it readily oxidizes on exposure to air, becoming black in color. All isotopes of radium are highly radioactive, with the most stable isotope being radium-226,...

, with the formula RaBr₂. It is produced during the separation of radium from uranium

Uranium

Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...

 ore

Ore

An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....

. This inorganic compound was discovered by Pierre

Pierre Curie

Pierre Curie was a French physicist, a pioneer in crystallography, magnetism, piezoelectricity and radioactivity, and Nobel laureate. He was the son of Dr. Eugène Curie and Sophie-Claire Depouilly Curie ...

 and Marie Curie

Marie Curie

Marie Skłodowska-Curie was a physicist and chemist famous for her pioneering research on radioactivity. She was the first person honored with two Nobel Prizes—in physics and chemistry...

 in 1898, which sparked a huge interest in radiochemistry

Radiochemistry

Radiochemistry is the chemistry of radioactive materials, where radioactive isotopes of elements are used to study the properties and chemical reactions of non-radioactive isotopes...

, especially radiotherapy. Since radium oxidizes rapidly in air and decomposes in water, the salt form is the preferred chemical form to work with . Even though the salt form is more stable, radium bromide is still a dangerous chemical that can explode under certain conditions.

History

After the Curies discovered radium, many people tried to get as much radium as possible to use it for medical purposes. However, it was not long until radium and radium salts were thought of as magical substances and were added to food, drinks, clothing, toys and more . Respectable journals in the early 1900’s published statements claiming that radium had no toxic effect.

Scientists were racing against each other trying to be the first to successfully use radium to cure health problems. Radium salts, including radium bromide, were most often used by placing the chemical in a tube that was then passed over or inserted into the problem site or tissue in the body. Many of the first scientists to try to determine radium’s uses were affected by their exposure to the radioactive material. Pierre Curie went so far as to self-inflict a severe chemical skin reaction by applying a radium source directly to his forearm . All types of therapeutic tests were performed for different skin diseases including eczema

Eczema

Eczema is a form of dermatitis, or inflammation of the epidermis . In England, an estimated 5.7 million or about one in every nine people have been diagnosed with the disease by a clinician at some point in their lives.The term eczema is broadly applied to a range of persistent skin conditions...

, lichen

Lichen

Lichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...

 and psoriasis

Psoriasis

Psoriasis is an autoimmune disease that appears on the skin. It occurs when the immune system mistakes the skin cells as a pathogen, and sends out faulty signals that speed up the growth cycle of skin cells. Psoriasis is not contagious. However, psoriasis has been linked to an increased risk of...

. It was not thought of until later that the radium could be used to treat cancerous diseases.

The main problem with the explosion of interest in radium was the lack of radium on earth itself. In 1913, it was reported that the Radium Institute had four grams of radium total, which at the time was more than half the world . Countries all over the world set out to make as much radium as possible, a time consuming and expensive task. It was reported in Science magazine in 1919 that the United States had produced approximately 55 grams of radium since 1913, which was also more than half the radium produced in the world at the time. A principal source for radium is pitchblende, which holds a total of 257 mg of radium per ton of U ₃O ₈ . Obviously with so little product recovered from such a large amount of material, it was difficult to find a large quantity of radium. This was the reason radium bromide became one of the most expensive materials on earth. It was desired by many all around the world and there was very little to go around. In 1921, it was stated in Times magazine that radium cost 17,000,000,000 Euros per ton compared to gold at 208,000 Euros and coal, as diamond, at 400,000,000 Euros .

A common reason that radium was added into almost everything at the time, including water and toys, was that people saw radium as fun, not harmful. Radium bromide was found to induce phosphorescence

Phosphorescence

Phosphorescence is a specific type of photoluminescence related to fluorescence. Unlike fluorescence, a phosphorescent material does not immediately re-emit the radiation it absorbs. The slower time scales of the re-emission are associated with "forbidden" energy state transitions in quantum...

 at normal temperatures . This led to the US army making and supplying luminous

Luminous

Luminous may refer to:* Luminous , the sixth release from American Futurepop band Cesium 137* Luminous , a 1998 short story collection by Greg Egan* Luminous, LLC, a contact lens company with headquarters in Portland, Oregon...

 watches to all soldiers. It also allowed for the invention of a spinthariscope

Spinthariscope

A Spinthariscope is a device for observing individual nuclear disintegrations caused by the interaction of ionizing radiation with a phosphor or scintillator.The spinthariscope was invented by William Crookes in 1903...

, which soon became the item everyone wanted in order to show that they were up to date on the new science discoveries at the time .

Properties

Radium bromide is a luminous chemical that causes the air surrounding it, even when encased in a tube, to glow and demonstrate all bands of the nitrogen spectrum. It is possible that the alpha radiation on the nitrogen

Nitrogen

Nitrogen is a chemical element that has the symbol N, atomic number of 7 and atomic mass 14.00674 u. Elemental nitrogen is a colorless, odorless, tasteless, and mostly inert diatomic gas at standard conditions, constituting 78.08% by volume of Earth's atmosphere...

 in the air causes this luminescence

Luminescence

Luminescence is emission of light by a substance not resulting from heat; it is thus a form of cold body radiation. It can be caused by chemical reactions, electrical energy, subatomic motions, or stress on a crystal. This distinguishes luminescence from incandescence, which is light emitted by a...

. Radium bromide is also very dangerous since the crystals occasionally explode. Helium gas can accumulate within the crystals which cause them to weaken and rupture. Another property of radium bromide is its ability to crystallize from an aqueous solution. It forms a dihydrate, very similar to the barium bromine compound.

Production

The chemical radium bromide is not found in nature; it is created. To extract radium from uranium or pitchblende ores, the most common practice is called the Curie method which it involves two major stages. The first stage is a chemical treatment to concentrate the radium as a combination of radium and barium. This is done by treating the ore with a barium salt and sulfuric acid which help the uranium, iron, copper, and other components become soluble. A residue containing gangue, barium, radium, and lead sulfates will be left over. The mixture will then be treated with sodium chloride to remove lead and convert radium and barium into carbonates that are insoluble in hydrochloric acid. The second step requires fractional crystallization

Fractional crystallization (chemistry)

In chemistry, fractional crystallization is a method of refining substances based on differences in solubility. If a mixture of two or more substances in solution is allowed to crystallize, for example by allowing the temperature of the solution to decrease, the precipitate will contain more of...

 to separate the barium from the radium . Because of the differences in solubility between radium and barium in bromide or chlorine, those two chemicals are chosen for the fractional crystallization. Once the radium is separated, radium bromide can be formed by dehydrating the dihydrate with a dry air stream at 200°C . Another method is to heat radium chloride to red heat with a dry hydrogen bromine gas stream .

Uses

Radium and radium salts were commonly used for treating cancer

Cancer

Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...

. However, many treatments that were used in the early 1900s are not used anymore because of the harmful effects radium bromide exposure caused. Some examples are anaemia, cancer, and genetic mutations

Mutation

In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic...

. Health effects from harmful amounts of radium exposure are tricky to diagnose because it is a cumulative health hazard. It cannot be diagnosed until years after exposure. In summary, there are not many practical uses for radium bromide anymore.