Oct 10, 2025 · A chemical reaction is a process in which one or more substances, the reactants, are converted to one or more different substances, the products. Substances are either …

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.

Sep 23, 2025 · The identification of pure substances and the analysis of chemical mixtures enable all other chemical disciplines to flourish. The importance of analytical chemistry has never …

Sep 15, 2025 · Krypton (Kr), chemical element, a rare gas of Group 18 (noble gases) of the periodic table, which forms relatively few chemical compounds. About three times heavier than …

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 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 …

Rubidium, chemical element of Group 1 (Ia) in the periodic table, the alkali metal group. Rubidium is the second most reactive metal and is very soft, with a silvery-white luster.

Sep 20, 2025 · Chemical formula, any of several kinds of expressions of the composition or structure of chemical compounds. The forms commonly encountered are empirical, molecular, …

Oct 22, 2025 · gold (Au), chemical element, a dense lustrous yellow precious metal of Group 11 (Ib), Period 6, of the periodic table of the elements. Gold has several qualities that have made …

Sep 12, 2025 · Chemical weapon - WMD, Toxins, Agents: Chemical weapons did not become true weapons of mass destruction (WMD) until they were introduced in their modern form in …