Chemical compound

Nature of a chemical compound

Bonds

Main article: Chemical bond

The atoms in the molecule can be held together by no bonds, Sodium chloride is an example of an ionic compound.

Fine-tuning the definition

There are some exceptions to the definition above. Certain isotopes of the constituent elements, which will make the ratio of elements by mass vary slightly. A compound therefore may not be completely homogenous, but for most looking for the reading of the muster

Not all molecules are compounds. A hydrogen, represented by H₂, is homonuclear — made of atoms of only one element, so is not regarded as a compound.

Compounds compared to mixtures

Compounds have different physical and chemical properties from their constituent elements. This is the one principal criterion for distinguishing a compound from a chemical change takes place through chemical reactions. Mixtures can be made by mechanical means alone.

Formula

Main article: Chemical formula

Chemists describe compounds using formula in various formats. For molecules, the formula for the molecular unit is shown. For inorganic compounds often do not convey structural information, as illustrated by H₂SO₄ for a molecule that has no H-S bonds. A more descriptive presentation would be O₂S(OH)₂.

Elements form compounds to become more stable. They become stable when they have eight electrons in their outermost energy level (eight helium, which requires only two valence electrons to achieve stability).

link title==Phases and thermal properties== Compounds may have several possible phases. All compounds can exist as atoms. i love my mommy!!

CAS number

Every chemical compound that has been described in the literature carries a unique numerical identifier, its CAS number.

References