Solid | Definition & Facts | Britannica
2024年10月29日 · Solid, one of the three basic states of matter, the others being liquid and gas. A solid forms from liquid or gas because the energy of atoms decreases when the atoms take up a relatively ordered, three-dimensional structure.
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 inch). A convenient unit of length for measuring atomic sizes is the angstrom (Å), defined as 10 −10 metre.
Atom - Development, Theory, Structure | Britannica
2024年10月8日 · Democritus believed that atoms were uniform, solid, hard, incompressible, and indestructible and that they moved in infinite numbers through empty space until stopped. Differences in atomic shape and size determined the various properties of matter.
Gas | Definition, State of Matter, Properties, Structure, & Facts ...
2024年9月27日 · Gas, one of the three fundamental states of matter, with distinctly different properties from the liquid and solid states. The remarkable feature of gases is that they appear to have no structure at all. They have neither a definite size nor shape, whereas ordinary solids have both a definite size.
Chemical bonding - Molecular, Solids, Structure | Britannica
2024年10月30日 · The most well-known example of a network solid is diamond, which consists of tetrahedrally bonded carbon atoms (see Figure 7). By virtue of the rigidity of its bonding structure, diamond is the hardest substance known and also the best conductor of heat.
Atomic model | Definition, History, Development, Examples,
His atomic model essentially consisted of solid spheres of different sizes for different types of atoms. The Greek atomic theory is significant historically and philosophically, but it was not based on observations of nature, measurements, tests, or experiments.
Amorphous solid | Properties, Structure & Examples | Britannica
Amorphous solid, any noncrystalline solid in which the atoms and molecules are not organized in a definite lattice pattern. Such solids include glass, plastic, and gel. Solids and liquids are both forms of condensed matter; both are composed of atoms in close proximity to each other.
Water | Definition, Chemical Formula, Structure, Molecule, & Facts ...
2024年11月3日 · water, a substance composed of the chemical elements hydrogen and oxygen and existing in gaseous, liquid, and solid states. It is one of the most plentiful and essential of compounds. A tasteless and odourless liquid at room temperature, it has the important ability to dissolve many other substances.
atom - Students | Britannica Kids | Homework Help
About 50 million atoms of solid matter lined up in a row would measure only 0.4 inch (1 centimeter). Atoms are thus far too small to see with the naked eye or even the highest-powered standard microscopes.
matter - Students | Britannica Kids | Homework Help
Most of the matter that people ordinarily observe can be classified into one of three states, or phases: solid, liquid, or gas. Solid matter generally possesses and retains a definite size and shape, no matter where it is situated.