If you memorize Periodic table, if you whip up exothermic reactions in your kitchen, Wenting Zhu and Yan Liang are here to renew your relationship with the elements.
To create the photos in their 300 photo group The beauty of chemistryToday, Zhu and Liang used infrared thermal imaging techniques, along with high-speed, time-lapse accurate imaging to immerse readers in the world of fine particles and the often stunning reactions between them. With atomic clarity, science writer Philip Ball narrates this visual tour through the under-appreciated chemical beauty that surrounds us, from describing the principles that generate the unique symmetry of a snowflake to linking the vibrant tendrils created by silicate salts to the origins of life itself.
Perhaps the simplest and startling of these concepts is the hydrogen bond, which unites the elements of literal life: water. Each water molecule consists of two hydrogen atoms attached to an oxygen atom, but oxygen has six electrons in its outer shell. Only two electrons are needed to form that chemical bond with hydrogen, so four negatively charged electrons, grouped by two in “hanging” pairs, are hovering there in the tiny space hoping to find a way to balance it. These pairs weakly pull hydrogen atoms bound to neighboring water molecules, forming short bonds of one trillionth of a second before they are broken apart and formed with another hydrogen atom. It is this constant, uninterrupted dance that allows the chemical movement that makes life possible, what the ball calls “molecular dialogue” that oscillates between order and chaos.
This chromium hydroxide precipitate is in the process of solidifying as it rotates and softens inside its container. This reaction occurs when two liquid compounds containing positive and negatively charged ions come together and make a molecular reel, where they share a trade. In this case, the ions of chromium chloride and NaOH are exchanged. The positively charged chromium and the negatively charged hydroxide molecules are attracted to each other because they are strongly balanced. They form tight bonds that freeze the molecules in place, creating a solid byproduct that doesn’t have room for all of these water molecules to fit neatly. The reaction also results in sodium chloride, commonly known as table salt, which dissolves well in water.