Alkaline Earth Metals

The alkaline earth metals are the second most reactive family of elements. Beryllium, magnesium, calcium, strontium, barium and radium are all shiny, and silvery-white. They all have low densities, melting points and boiling points, and they tend to form solutions with a pH greater than 7.

Beryllium is the only alkaline earth metal not to react with water. One of its naturally occurring compounds is emerald. Calcium is needed for healthy bones, and plants need magnesium to form the chlorophyll molecules they use for photosynthesis. Strontium is important to sea life, particularly for hard corals, which use strontium to build their exoskeletons.

Radioactive radium was discovered by Marie Curie and her husband Pierre, and was used in glow-in-the-dark paint until the 1960s!

Alzheimer's is the most common form of dementia, but we don't yet understand what causes the disease, or how to treat it. Alzheimer's causes amyloid plaques to form in the brain that disrupt its normal function, and researchers used X-ray spectromicroscopy on the Scanning X-ray Microscopy beamline (I08) to characterise the precise distribution and chemical state of iron and calcium compounds within amyloid plaques.

Their study revealed, in unprecedented detail at nanoscale resolution, the properties of iron and calcium compounds in plaques from individuals who had Alzheimer's disease. Their findings extend current hypotheses about how these and other metallic species may contribute to the development of Alzheimer's disease and could help direct future innovative diagnosis and treatment of the disease. Read more here.

Materials such as seashells, teeth and bones often have remarkable physical properties that are far better than those of equivalent artificially produced substances. Biominerals exhibit features such as complex morphologies, hierarchical structures and properties optimised for their roles that make them a unique inspiration for materials design. Researchers are particularly interested in how organisms generate materials with strength and toughness from weak, brittle minerals such as calcium carbonate and calcium phosphate.

An investigation using the High Resolution Powder Diffraction beamline (I11) provided new insights into the mechanical properties of inorganic/organic nanocomposites and determined the origin of the hardening effects of small organic molecules within single crystals. These results are of particular significance to the mechanical properties of single crystal biominerals and open up the possibility of using the same strategy to tailor the mechanical properties of a wide range of materials. Read more here.

Calcium carbonate has three main forms or ''polymorphs'': vaterite, calcite and aragonite. Project M was an innovative ''citizen science'' project, involving pupils from 100 schools and launched by well-known scientist Professor Alice Roberts. The initiative allowed 14-18-year-olds to contribute to cutting-edge research, take part in genuine experiments and publish their results in a scientific peer-reviewed journal.

The project aimed to increase our understanding of calcium carbonate and how different additives affect the different form of calcium carbonate produced. Being able to create different types easily could be incredibly important for manufacturing.

Each participating school made ten samples using specially selected additives. The Diamond team analysed all of the samples in 24 hours, on the I11 beamline, to produce a giant set of results. This was the first time that UK schools were able to prepare and run samples at Diamond, and Project M was awarded the Royal Society of Chemistry Inspiration & Industry Award for 2018. Read more here.

Gypsum is one of three crystalline phases of calcium sulfate, alongside bassanite and anhydrite. Gypsum is one of the most common minerals on Earth, but we don't fully understand how it forms from ions in solution. Researchers used the Small Angle Scattering and Diffraction beamline (I22) to follow the formation of gypsum in situ for the first time.

Using Small and Wide Angle X-ray Scattering (SAXS and WAXS), they were able to show that gypsum forms in a four-stage process, beginning with the formation of well-defined calcium sulfate nanobricks, which self-assemble to form a crystalline structure. Time-resolved measurements allowed them to follow the growth in real time. Their results give a new insight into gypsum nucleation and growth, which could potentially be used to understand its formation in nature in the future.

Large deposits of gypsum and anhydrite are found naturally on Earth. Bassanite is not naturally abundant, but has an essential role in the construction industry, with 100 billion tones of it produced annually as plaster of Paris. Evidence of natural deposits of gypsum and bassanite has also recently been found on Mars. Read more here.

No matter how careful you are when you fill the dishwasher, there's no way of guaranteeing every item will come out clean. It's especially annoying when the wine glasses come out spotty, rather than sparkling. The problem is limescale - calcium carbonate - being left behind by the water, and it's more of a problem in hard water areas.

Until recently, the solution for this issue was adding a phosphate-based ''inhibitor'' to prevent the calcium build-up from forming. However, we have since discovered that although phosphate is non-toxic, it can build up in the environment and have damaging effects. High levels of phosphorus in rivers and lakes lead to excessive plant growth and algal blooms, low oxygen levels and a decrease in biodiversity.

The EU banned phosphates in consumer laundry detergent in 2013, and a ban on the use of phosphates in dishwasher detergent followed in 2017. Scientists are searching for less damaging chemicals that can do the same job, but six different forms of calcium carbonate, known as polymorphs, have been identified, and they don't all react with inhibitors in the same way.

A team of researchers developed a lab-based model dishwasher system to rapidly screen 28 chemical candidates. They used powder X-ray diffraction (PXRD) on the Small Molecule Single-Crystal Diffraction beamline (I19) to examine the calcium deposits. Their results showed that, although no single chemical could match the performance of the phosphate-based inhibitor, two used in combination did the trick. Their combined cleaning power was confirmed in a commercial dishwasher - a truly sparkling result! Read more here.

On Earth, our bones are continuously formed and reabsorbed, which gives them resistance to fractures. The calcium balance for a healthy person is (the difference between calcium intake and excretion) is just about zero. For astronauts in microgravity, however, it's a very different story. Their calcium balance decreases to about -250 mg/day, leading to bone loss and an increased risk of kidney stones. Even though astronauts take a lot of exercise, and eat a balanced diet, it can take several years back on Earth for them to recover.