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Simple illustration of particles in the solid state – they are closely packed to each other. In a solid, constituent particles (ions, atoms, or molecules) are closely packed together. The forces between particles are so strong that the particles cannot move freely but can only vibrate. As a result, a solid has a stable, definite shape, and a ...
The particles are held very close to each other. Amorphous solid: A solid in which there is no far-range order of the positions of the atoms. Crystalline solid: A solid in which atoms, molecules, or ions are packed in regular order. Quasicrystal: A solid in which the positions of the atoms have long-range order, but this is not in a repeating ...
One good example of this is the quartz form of silicon dioxide, or SiO 2. In the vast majority of silicates, the Si atom shows tetrahedral coordination by 4 oxygens. All but one of the crystalline forms involve tetrahedral {SiO 4} units linked together by shared vertices in different arrangements. In different minerals the tetrahedra show ...
At a microscopic level, the constituent "particles" of matter such as protons, neutrons, and electrons obey the laws of quantum mechanics and exhibit wave–particle duality. At an even deeper level, protons and neutrons are made up of quarks and the force fields that bind them together, leading to the next definition.
The basic idea that matter is made up of tiny indivisible particles is an old idea that appeared in many ancient cultures. The word atom is derived from the ancient Greek word atomos, [a] which means "uncuttable". But this ancient idea was based in philosophical reasoning rather than scientific reasoning.
An atom consists of a small, heavy nucleus surrounded by a relatively large, light cloud of electrons. An atomic nucleus consists of 1 or more protons and 0 or more neutrons. Protons and neutrons are, in turn, made of quarks. Each type of atom corresponds to a specific chemical element. To date, 118 elements have been discovered or created.
Many crystal structures are based on a close-packing of a single kind of atom, or a close-packing of large ions with smaller ions filling the spaces between them. The cubic and hexagonal arrangements are very close to one another in energy, and it may be difficult to predict which form will be preferred from first principles.
A proton is composed of three quarks and held together with the strong interaction. Particles can also be classified according to composition. Composite particles refer to particles that have composition – that is particles which are made of other particles. [16] For example, a carbon-14 atom