Atom | Definition, Structure, History, Examples, Diagram, & Facts ...
2024年10月8日 · All atoms are roughly the same size, whether they have 3 or 90 electrons. Approximately 50 million atoms of solid matter lined up in a row would measure 1 cm (0.4 …
Hydrogen chloride | Definition, Formula, Properties, & Facts
2024年11月15日 · hydrogen chloride (HCl), a compound of the elements hydrogen and chlorine, a gas at room temperature and pressure. A solution of the gas in water is called hydrochloric …
Rutherford model | Definition, Description, Image, & Facts
2024年10月23日 · The model described the atom as a tiny, dense, positively charged core called a nucleus, in which nearly all the mass is concentrated, around which the light, negative …
Covalent bond | Definition, Properties, Examples, & Facts | Britannica
2024年10月29日 · Covalent bond, in chemistry, the interatomic linkage that results from the sharing of an electron pair between two atoms. The binding arises from the electrostatic …
Carbon | Facts, Uses, & Properties | Britannica
2024年11月9日 · Two of its well-defined forms, diamond and graphite, are crystalline in structure, but they differ in physical properties because the arrangements of the atoms in their structures …
Molecule | Definition, Examples, Structures, & Facts | Britannica
2024年10月21日 · Molecule, a group of two or more atoms that form the smallest identifiable unit into which a pure substance can be divided and still retain the composition and chemical …
Nitrogen | Definition, Symbol, Uses, Properties, Atomic Number,
2024年10月30日 · The natural abundance of nitrogen in Earth’s crust is 0.3 part per 1,000. The cosmic abundance—the estimated total abundance in the universe—is between three and …
Calcium | Definition, Properties, & Compounds | Britannica
2024年11月12日 · Calcium constitutes 3.64 percent of Earth’s crust and 8 percent of the Moon’s crust, and its cosmic abundance is estimated at 4.9 × 10 4 atoms (on a scale where the …
Sulfur | Definition, Element, Symbol, Uses, & Facts | Britannica
Only eight of the 30 seem to be unique; five contain rings of sulfur atoms and the others contain chains. In the rhombohedral allotrope, designated ρ-sulfur, the molecules are composed of …
Fatty acid | Definition, Structure, Functions, Properties, & Examples ...
2024年11月7日 · Fatty acid, important component of lipids in plants, animals, and microorganisms. Generally, a fatty acid consists of a straight chain of an even number of …