elektronipistettä

Elektronipistettä, also known as electron dot notation or Lewis dot structure, is a diagrammatic representation used in chemistry to show the valence electrons of an atom or molecule. In this notation, dots are used to represent the valence electrons, which are the electrons in the outermost shell of an atom and are involved in chemical bonding. Each dot represents one valence electron.

When representing a single atom, the dots are typically placed around the chemical symbol of the element. The number of dots corresponds to the number of valence electrons that atom possesses. For example, an oxygen atom has six valence electrons, so its electron dot structure would show the symbol 'O' surrounded by six dots.

In molecules, the electron dot notation is extended to show how atoms share or transfer electrons to form chemical bonds. Covalent bonds are represented by pairs of dots shared between two atoms, indicating that the electrons are being shared to form a covalent bond. Lone pairs of electrons, which are valence electrons not involved in bonding, are also shown as pairs of dots around the atom.

Lewis dot structures are a fundamental tool in understanding chemical bonding, predicting molecular geometry, and determining the reactivity of substances. They provide a simple yet powerful way to visualize the distribution of electrons within a chemical species. This notation was developed by Gilbert N. Lewis in the early 20th century.