Related concepts:

Isotopes:

Isotopes refer to atoms (nuclides) with the same nuclear charge but different atomic weights, which are called isotopes.

Nuclides:

Nuclides refer to atoms with a certain number of protons and a certain number of neutrons.

Variant:

Allotrope (also called allotrope): Different simple substances composed of the same element, such as graphite and diamond, oxygen and ozone, white phosphorus and red phosphorus. The physical and chemical properties of allotropes are obviously different because of their different molecular composition or crystal structure. For example, diamond is an atomic crystal with a regular tetrahedral spatial network structure formed by covalent bonds between carbon atoms; Graphite is a kind of transition crystal with layered structure. The carbon atoms in the layer are covalently bonded to form a regular hexagonal network structure, and the distance between layers is large, which is equivalent to the action of intermolecular forces. Diamond is the hardest substance and cannot conduct electricity; However, graphite has lower hardness, relative sliding between layers, good conductivity and more active chemical properties than diamond. Another example is white phosphorus and red phosphorus. White phosphorus is composed of tetrahedral molecules (P4), which is a white waxy solid, highly toxic, easily soluble in CS2, with a low ignition point (40℃) and spontaneous combustion in air. Red phosphorus is a complex layered crystal, red powder, non-toxic, insoluble in CS2, and its ignition point is 240℃. In the absence of air, when the heating temperature rises to 260℃, white phosphorus is transformed into red phosphorus, which is sublimated when heated at 4 16℃, and then cooled by steam to become white phosphorus. The molecular compositions of O2 and O3 are different, and O3 is a more active oxidant than O2.