Sep 26, 2025 · 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.

Oct 10, 2025 · Substances are either chemical elements or compounds. A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products.

Sep 23, 2025 · Cooking, fermentation, glass making, and metallurgy are all chemical processes that date from the beginnings of civilization. Today, vinyl, Teflon, liquid crystals, …

Oct 17, 2025 · A chemical element is any substance that cannot be decomposed into simpler substances by ordinary chemical processes. Elements are the fundamental materials of which …

Chemical industry, complex of processes, operations, and organizations engaged in the manufacture of chemicals and their derivatives. Raw materials include fossil fuels and …

Oct 30, 2025 · This article begins by describing the historical evolution of the current understanding of chemical bonding and then discusses how modern theories of the formation …

Nov 1, 2025 · Chemical formula, any of several kinds of expressions of the composition or structure of chemical compounds. The forms commonly encountered are empirical, molecular, …

CHEMICAL meaning: 1 : of or relating to chemistry; 2 : working by means of chemicals

Oct 27, 2025 · Fluorine is found in nature only in the form of its chemical compounds, except for trace amounts of the free element in fluorspar that has been subjected to radiation from …

Sep 12, 2025 · In modern warfare, chemical weapons were first used in World War I (1914–18). Like nuclear and biological weapons, chemical weapons are often classified as weapons of …

Chemical equilibrium is the condition in the course of a reversible chemical reaction in which no net change in the amounts of reactants and products occurs. A reversible chemical reaction is …

Sep 24, 2025 · In its chemical reactivity, lithium more closely resembles Group 2 (IIa) of the periodic table than it does the other metals of its own group. It is less reactive than the other …

Oct 10, 2025 · Chemical reaction - Energy, Reactants, Products: Energy plays a key role in chemical processes. According to the modern view of chemical reactions, bonds between …

A chemical change (that is, a chemical reaction) is one in which the organization of the atoms is altered. An example of a chemical reaction is the burning of methane in the presence of …

Oct 19, 2025 · The principal chemical application of bismuth is in the form of bismuth phosphomolybdate (BiPMo 12 O 40), which is an effective catalyst for the air oxidation of …

Oct 31, 2025 · Mercury, chemical element, liquid metal of Group 12 of the periodic table. Mercury is the only elemental metal that is liquid at room temperature. Mercury is silvery white and …

4 days ago · oxalic acid chemical compound Also known as: ethanedioic acid Britannica Editors Nov. 4, 2025 • History

Rust is the result of a chemical reaction between metal, typically iron, and oxygen in the presence of moisture. This process, known as oxidation, transforms the metal into a new compound, …

Oct 24, 2025 · Ionic bond, type of linkage formed from the electrostatic attraction between oppositely charged ions in a chemical compound. Such a bond forms when the valence …

Sep 29, 2025 · Chlorine is the best known of the halogen elements. The free element is widely used as a water-purification agent, and it is employed in a number of chemical processes. …