Victor Grignard researched phosgene and mustard gas for the French army in the First World War but this came after the use of chlorine by the German army at Ypres in 1915. The use of chlorine as a weapon of mass destruction was developed by Fritz Haber who also supervised its release in the trenches. Rutherford and Moseley worked together on the structure of atoms. Moseley who used X-rays to show the importance of atomic number was killed at the Battle of Gallipoli on 10 August 1915. 

When light falls on silver bromide in a photographic film it converts the silver ions into metallic silver. This reduction process is further enhanced when the film is developed using a reducing agent such as hydroquinone. Once the desired level of reduction is achieved the development process is halted by washing in a dilute acid, such as ethanoic acid, and then the undeveloped silver bromide is removed by dissolving it in a thiosulfate solution, a process called fixing. The reaction between silver bromide and sodium thiosulfate is AgBr(s) + 2Na₂S₂O₃(aq) → Na₃Ag(S₂O₃)₂(aq) + NaBr(aq). The film is then washed in water to remove all the soluble salts. The printing of the positive photograph from the negative image on the film follows a similar process.

Serendipity requires both a chance event and the mental ability to understand the occurrence and realise its potential. Many drugs such as penicillin and sulphanilamide have been discovered by serendipity. Cis-platin, PtCl₂(NH₃)₂, was discovered through serendipity when Barnett Rosenberg noticed in 1965 that when he used platinum electrodes to pass electricity through a solution of bacteria, the bacterial cells stopped dividing, although they kept growing to up to 300 times their normal length. He assumed the platinum was inert (which is why he chose to use it for the electrodes) and initially thought the effect was due to the electric current. It was only later that he realised that a compound cis-platin was being formed at the electrodes and it was this that stopped the cells dividing. Cis-platin is now a very effective drug against testicular cancer and other forms of cancer.

Linus Pauling was awarded the Nobel Prize in Chemistry in 1954 for his work on bonding. This included the concepts of hybridization, the electronegativities of the elements and the structures of proteins. In 1962 he was awarded the Nobel Peace Prize for his work campaigning against the above-ground testing of nuclear weapons and the spread of nuclear weapons. Marie Curie also was awarded two Nobel Prizes (in Physics in 1903 and in Chemistry in 1911).  She is still the only woman to have won the Nobel Prize twice.

William Perkin was only aged 18 when he was working under the instruction of Hofmann at what is now Imperial College London. He was asked to try to synthesise quinine from aniline. Whilst working at home he produced a substance with an intense purple colour. This was the first aniline dye and Perkin set up a factory to develop and mIB Docs (2) Teamfacture the dye.

Søren Sørensen (1868 – 1939) was a Danish chemist who worked in the Carlsberg brewery laboratory in Copenhagen. He devised the pH system in 1909.

The element Kurchatov (symbol Ku) was discovered in 1964 by nuclear scientists working at the Joint Institute of Soviet Research in the USSR  by bombarding plutonium-242 with neon-22. In 1969 the element was independently synthesised in the University of California, Berkeley by bombarding californium-249 with carbon-12.  As the Americans were the first to publish they claimed the right to name it and called it Rutherfordium. In 1997 IUPAC formally agreed on the name Rutherfordium (Rf) but honoured the Soviets by naming element 105 Dubnium (symbol Db) after Dubna, the site of the Joint Institute of Soviet Research.

In the Lewis structure of oxygen all the electrons are in pairs whereas paramagnetism is associated with unpaired electrons. The Lewis theory of bonding whereby atoms share their valence electrons to try to achieve a noble gas electron configuration is a simplified theory based on the false assumption that all the electrons in a valence shell are identical, whereas in reality they exist in sub-levels with different energies.

In 1669 Brandt was attempting to create the philosopher’s stone (which could transform base metals such as lead into gold) by heating strongly a mixture of sand and charcoal with a distillate obtained from about 1,200 gallons of urine. He produced a white substance which gleamed in the air. He named it phosphorus after the Latin term for giving off light. Brandt thought it was composed of a mixture of the four known elements at the time, fire, earth, air and water. It was not until Lavoisier defined an element more than one hundred years later that the significance of the accidental discovery was realised.

'The Alchemist, in Search of the Philosopher's Stone' by Joseph Wright of Derby showing the discovery of phosphorus.

Strontium is absorbed by the body through soils and through the food chain where it substitutes for calcium. Depending on its source the ratio of ⁸⁷Sr to ⁸⁶Sr varies. As the strontium is absorbed by the body it becomes fixed in tooth enamel as the person grows thus providing a permanent record of the environment that the person grew up in. Analysis of the ⁸⁷Sr to ⁸⁶Sr ratio of the teeth found in her tomb in Magdeburg confirmed that she had spent the early part of her childhood in southern England.