Element 5: Boron, found in eye drops, pyrotechnic flares, and laboratory glassware.

Here’s element number five in the series of element graphics I’m producing with the Royal Society of Chemistry for the International Year of the Periodic Table.

Boron is found as a preservative and buffer in eye drops and contact lens solutions in the form of borax (sodium tetraborate). You might be more familiar with borax as an ingredient in homemade slimes, where it forms crosslinks that lend slime its gooey properties.

Boron is also used in pyrotechnic flares to give them a distinctive green colour. Boron carbide might also offer a more environmentally-friendly way to make green fireworks.

Finally, boron trioxide is used to make heat-resistant borosilicate glass, which is commonly used for laboratory glassware. Borosilicate glass was also previously used to make Pyrex, but it has since been replaced by tempered soda-lime glass.