Chemical compound | Definition, Examples, & Types | Britannica
All the matter in the universe is composed of the atoms of more than 100 different chemical elements, which are found both in pure form and combined in chemical compounds.

Chemistry | Definition, Topics, Types, History, & Facts | Britannica
Cooking, fermentation, glass making, and metallurgy are all chemical processes that date from the beginnings of civilization. Today, vinyl, Teflon, liquid crystals, semiconductors, and superconductors represent the fruits of chemical technology.

Chemical element | Definition, Origins, Distribution, & Facts | Britannica
A chemical element is any substance that cannot be decomposed into simpler substances by ordinary chemical processes. Elements are the fundamental materials of which all matter is composed. Learn more about the origins, distribution, and characteristics of chemical elements in this article.

Chemical reaction | Definition, Equations, Examples, & Types - Britannica
Substances are either chemical elements or compounds. A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products.

Periodic table | Definition, Elements, Names, Symbols, Groups, Charges ...
Periodic table, in chemistry, is an organized array of all the chemical elements in order of increasing atomic number. When the elements are thus arranged, there is a recurring pattern in which elements in the same column (group) have similar properties.

Sodium bicarbonate | Definition, Uses, & Formula | Britannica
Sodium bicarbonate, white crystalline or powdery solid that is a source of carbon dioxide and so is used as an ingredient in baking powders, in effervescent salts and beverages, and as a constituent of dry-chemical fire extinguishers.

Nitric oxide | Uses, Facts, & Definition | Britannica
Nitric oxide, colourless toxic gas that has important chemical signaling functions in animals and is a serious air pollutant.

Lead | Definition, Uses, Properties, & Facts | Britannica
What is lead as a chemical element? What does lead look like and what is its symbol on the periodic table? Where is lead found in nature? What are some uses of lead in everyday life?

Cellular respiration | Definition, Equation, Cycle, Process, Reactants ...
Cellular respiration, the process by which organisms combine oxygen with foodstuff molecules, diverting the chemical energy in these substances into life-sustaining activities and discarding, as waste products, carbon dioxide and water.

Chemical industry | Overview, Importance, & History | Britannica
Chemical industry, complex of processes, operations, and organizations engaged in the manufacture of chemicals and their derivatives. Raw materials include fossil fuels and inorganic chemicals.