Chemistry is the science of properties, composition, and structure of substances — that is, elements and compounds — their transformations, and the energy that is released or absorbed in the process. Chemistry is in just about everything, from the chemical reactions that influence our emotions to the chemicals in everyday things like clothing and electronics.
Humans have been studying chemistry since the ancient Greeks, who believed there were only four elements: air, earth, fire, and water. The first modern chemist was an 18th Century French nobleman named Antoine Lavoisier who developed an experimental theory of the chemical reactivity of oxygen. He also helped create a system for naming chemical substances that were groundbreaking for its time.
In 1869, a Russian chemist named Dmitri Mendeleev further revolutionized the field of chemistry by inventing what would eventually become the Periodic Table, a classification of all the known chemical elements in the world. The Periodic Table is very important not only because it classifies chemical elements, but because it breaks down the complex way they are related to one another in a way that is easy to understand. The table organizes the chemical elements by atomic number (the number of protons in the nucleus of an atom of an element), beginning with the element with the lowest atomic number (hydrogen) to the one with the highest (oganesson).
Mendeleev was unable to complete the Periodic Table in his lifetime. However, it has come to total 118 elements — far more than the ancient Greeks ever imagined — and is still being updated. The last update, in 2016, included the addition of four new elements: nihonium, moscovium, tennessine, and oganesson.
Celebrate National Chemistry Week
Want to learn more about chemistry? National Chemistry Week, founded by the American Chemical Society (ACS), is an annual event that celebrates the contributions of chemistry and its importance to our everyday lives. You won’t want to miss this year’s theme: “Fast or Slow…Chemistry Makes It Go!” To celebrate, check out these events on the ACS website.
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