Chemistry

Manganese, the second-most common metal in the earth's crust, rapidly changes between oxidation states while reacting with other elements in the environment. It is an element critical to many life processes and helps plants produce oxygen during photosynthesis.  Manganese is present in the environment in three forms — manganese(II), manganese(III) and manganese(IV) — the difference related to the oxidation state, or number of electrons present. When elements lose or gain an electron, the oxidation state changes in a "redox reaction," like when iron turns into rust by…

When it comes to what's for dinner – or breakfast and lunch for that matter - too many people suffer from chemophobia, an irrational fear of chemicals that pose no risk to our health. Chemistry Professor Gordon Gribble argues that low doses of chemicals in modern food are inherent, typically harmless and often highly beneficial. He says most people don't know they are routinely exposed to a host of compounds in non-toxic concentrations in what they eat and drink each day. Even the air we breathe, whether in big cities or the countryside, is full of naturally occurring and synthetic…

A young child buried in the medieval town of Ribe in Denmark 800 years ago had an unpleasant life even before that - because the child had been given a large dose of mercury in an attempt to cure a severe, ongoing illness.  A new methodology developed by chemist Kaare Lund Rasmussen from University of Southern Denmark and colleagues can reveal an unprecedented amount of details about the time even shortly before a person's death. Mercury is of particular interest for the archaeologists as many cultures in different part of the world have been in contact with the rare (and toxic) element…

Soylent is getting ready to feed people - I will spare you a joke about the 1973 dystopian film "Soylent Green", inspired by Harry Harrison's "Make Room! Make Room!", since you already made it in your head.(1) It's not meat of unknown origin, it is instead a nutrient drink that the company wants to have in grocery stores. It might work. There is the Prepper market, of course, and then the hipster factor - they are no dummies picking that name for their product - but there may also be a market for people who just don't care about food. The way some people are asexual, some are also a-culinary…

Last week, a study published in the journal Human Reproduction reported that bisphenol-A (BPA), a compound widely used to make polycarbonate plastic and epoxy resins, altered maturation of human oocytes in vitro. Specifically, at high concentrations of BPA, oocyte maturation decreased while the incidence of oocyte degeneration increased. In an accompanying press release, the authors suggested that BPA “may cause a significant disruption to the fundamentals of the human reproductive process and may play a role in human infertility.” But does this study really support such a far-reaching…

Pizza may be symptomatic of many First World problems: 50% of Europe is overweight or obese and there is concern about hypertension, type 2 diabetes, stroke or certain cancers linked to nutrition. So what do European politicians do? They set out to fund pizza science so that it still tastes great but is less likely to kill you instead of, you know, eating less pizza.  Don't get me wrong, I love capitalism. I have zero problem with Sugar Frosted Chocolate Bombs on Saturday morning cartoons or some guy from "The Sopranos" telling me women will like me more if I pour tequila from a bottle…

Over 2,000 years ago, gold- and silversmiths developed a variety of techniques, including using mercury like a glue to apply thin films of metals to statues and other objects. They developed thin-film coating technology that is unrivaled by today's process for producing DVDs, solar cells, electronic devices and other products and used it on jewels, statues, amulets and more common objects. Workmen over 2000 years ago managed to make precious metal coatings as thin and adherent as possible, which not only saved expensive metals but improved resistance to wear caused from continued use and…

Synthetic materials made from organic polymers, like polyurethane foams, usually burn very well due to their high carbon content. They not only burn easily; depending on their chemical composition they can produce toxic gases such as hydrogen cyanide or carbon monoxide. Upholstered furniture and mattresses commonly use polyurethane foams so they have to be treated with flame retardants.  Conventional halogenated flame retardants such as tri(chloropropyl) phosphate (TCPP) and brominated flame retardants, such as  polybrominated diphenyl ethers (PBDE), are now suspected of being…

A family of molecules called TAML activators provide an environmentally friendly method for breaking down toxic compounds that contaminate water, including endocrine disruptors. Endocrine disrupters, which are found in almost 25 percent of our streams, rivers and lakes, can disrupt the normal functions of the endocrine system by mimicking or blocking the activities of hormones in wildlife leading to impaired development. While the connections between the adverse effects of endocrine disrupting water contaminants on aquatic organisms and human health have yet to be established, animal studies…

Standard atomic weights for chemical elements are not quite as constant as you might think - along with the speed of light and the attraction of gravity there are some exceptions. Hold on to your Newtonian hat and prepare for the possibility of elementary nuances.  The importance of determining precise atomic weights has long been recognized. As far back as 1882, Frank W. Clarke, then a professor at the University of Cincinnati, prepared a table of atomic weights for use in science, industry, and trade. He carried on this work as Chief Chemist of the USGS (1883-1924). Clarke was a…