Bromine Facts (Atomic Number 35 or Br)

Bromine Facts (Atomic Number 35 or Br) Bromine is a halogen element with atomic number 35 and element symbol Br.  At room temperature and pressure, it is one of the few liquid elements. Bromine is known for its brown color and characteristic acrid odor. Here is a collection of facts about the element: Bromine Atomic Data Atomic Number: 35 Symbol: Br Atomic Weight: 79.904 Electron Configuration: [Ar]4s23d104p5 Word Origin: Greek bromos, which means stench Element Classification: Halogen Discovery: Antoine J. Balard (1826, France) Density (g/cc): 3.12 Melting Point ( °K): 265.9 Boiling Point ( °K): 331.9 Appearance: reddish-brown liquid, metallic luster in solid form Isotopes: There are 29 known isotopes of bromine ranging from Br-69 to Br-97. There are 2 stable isotopes: Br-79 (50.69% abundance) and Br-81 (49.31% abundance). Atomic Volume (cc/mol): 23.5 Covalent Radius (pm): 114 Ionic Radius: 47 (5e) 196 (-1e) Specific Heat (20 °C J/g mol): 0.473 (Br-Br) Fusion Heat (kJ/mol): 10.57 (Br-Br) Evaporation Heat (kJ/mol): 29.56 (Br-Br) Pauling Negativity Number: 2.96 First Ionizing Energy (kJ/mol): 1142.0 Oxidation States: 7, 5, 3, 1, -1 Lattice Structure: Orthorhombic Lattice Constant (Ã…): 6.670 Magnetic Ordering: nonmagnetic Electrical Resistivity (20  °C): 7.8Ãâ€"1010 ÃŽ ©Ã‚ ·m Thermal Conductivity (300 K): 0.122 W ·m−1 ·K−1 CAS Registry Number: 7726-95-6 Bromine Trivia Bromine is named after the Greek word bromos meaning stench because bromine smells... stinky. Its a sharp, acrid odor thats hard to describe, but many people know the smell from the elements use in swimming pools.Bromine was nearly discovered by two other chemists before Antoine Jerome Balard published his discovery. The first was in 1825 by the German chemist Justus von Liebig. He was sent a sample of salt water to analyze from a nearby town. He thought the brown liquid he separated from the salt water was a simple mixture of iodine and chlorine. After he learned of Balards discovery, he went back and checked. His liquid was the newly discovered bromine. The other discoverer was a chemistry student named Carl Loewig. He separated the same brown liquid in 1825 from another sample of salt water. His professor asked him to prepare more of the brown liquid for further testing and soon learned of Balards bromine.Elemental bromine is a toxic substance and can cause corrosion burns when ex posed to skin. Inhalation can cause irritation, in low concentrations, or death, in high concentration. Although toxic as a pure element and in high doses, bromine is an essential element for animals. The bromide ion is a cofactor in collagen synthesis.In World War I, xylyl bromide and related bromine compound were used as poison gas.Compounds containing bromine in the -1 oxidation state are called bromides.Bromine is the tenth most abundant element in sea water with an abundance of 67.3 mg/L.Bromine is the 64th most abundant element in the Earths crust with an abundance of 2.4 mg/kg.At room temperature, elemental bromine is a reddish-brown liquid. The only other element that is a liquid at room temperature is mercury.Bromine is used in many fire retardant compounds. When brominated compounds burn, hydrobromic acid is produced. The acid acts as a flame retardant by interfering with the oxidation reaction of combustion. Nontoxic halomethane compounds, such as bromochloromethane and bromotrifluoromethane, are used in submarines and spacecraft. However, they are not generally useful becau se they are expensive and because they damage the ozone layer. Bromide compounds used to be used as sedatives and anticonvulsants. Specifically, sodium bromide and potassium bromide were used in the 19th and 20th century until they were replaced by chloral hydrate, which was in turn replaced by barbituates and other drugs.The ancient royal purple dye called Tyrian Purple is a bromine compound.Bromine was used in leaded fuels to help prevent engine knock in the form of ethylene bromide.Herbert Dow, founder of the Dow Chemical Company started his business separating bromine from brine waters of the Midwestern United States. Sources Duan, Defang; et al. (2007-09-26). Ab initio studies of solid bromine under high pressure. Physical Review B. 76 (10): 104113. doi:10.1103/PhysRevB.76.104113Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 0-08-037941-9.Haynes, William M., ed. (2011). CRC Handbook of Chemistry and Physics (92nd ed.). Boca Raton, FL: CRC Press. p. 4.121. ISBN 1439855110.Weast, Robert (1984). CRC, Handbook of Chemistry and Physics. Boca Raton, Florida: Chemical Rubber Company Publishing. pp. E110. ISBN 0-8493-0464-4.Weeks, Mary Elvira (1932). The discovery of the elements: XVII. The halogen family. Journal of Chemical Education. 9 (11): 1915. doi:10.1021/ed009p1915 Return to the Periodic Table

Word Choice Causal vs. Casual - Writing Tips with Get Proofed!

Word Choice Causal vs. Casual - Writing Tips with Get Proofed! Word Choice: Causal vs. Casual Sometimes typos are obvious. If you write â€Å"teh† instead of â€Å"the,† for example, it’s easy to spot the error. Half the time your phone or computer will autocorrect it for you! But things get trickier with â€Å"causal† and â€Å"casual.† One keystroke out of place here and you get a completely different word. And since â€Å"causal† and â€Å"casual† are both proper words, you can’t rely on autocorrect to help you out. Luckily, then, we’re here to help out with our quick guide to how these words should be used. Causal (Related to Causation) â€Å"Causal† means â€Å"related to causation.† We use it when discussing relationships of cause and effect: Our study looks at the causal relationship between weather and mood. The key thing to remember with this word is that it’s always related to the cause of something. The â€Å"causal relationship† above, for example, refers to how weather affects how we feel. The weather today will start out gloomy, but by lunch it will be looking more upbeat. Casual (Informal or Relaxed) The word â€Å"casual† has a few different uses, but it usually refers to being informal, relaxed, or unconcerned about something. For example, we might say: To the casual observer, this wedding looked just like any other. Here, â€Å"casual observer† implies a non-expert or someone who is not paying close attention. We could also say: You can’t turn up to a wedding ceremony in casual clothes! In this case, â€Å"casual clothes† refers to jeans, trainers, or other informal clothing. If we can see your knees, youre dressed casually. A slightly different use is to mean â€Å"irregular† or â€Å"temporary,† such as when we talk about â€Å"casual work† (i.e., work without regular hours). Even this sense of â€Å"casual† draws on the idea of an informal or relaxed relationship, though, so it isn’t too far from the other uses outlined above. Causal or Casual? As you can see, â€Å"causal† and â€Å"casual† have very different uses. The good news is that this makes it easy to remember the difference. The bad news is that a minor typo could lead to a big error! The best way to avoid mistakes with these words is to proofread your work carefully. And remember: Causal = Related to causation Casual = Informal or relaxed