Search results
Results From The WOW.Com Content Network
[1] [2] [3] Introduced by Gilbert N. Lewis in his 1916 article The Atom and the Molecule, a Lewis structure can be drawn for any covalently bonded molecule, as well as coordination compounds. [4] Lewis structures extend the concept of the electron dot diagram by adding lines between atoms to represent shared pairs in a chemical bond.
This would result in the geometry of a regular tetrahedron with each bond angle equal to arccos(− 1 / 3 ) ≈ 109.5°. However, the three hydrogen atoms are repelled by the electron lone pair in a way that the geometry is distorted to a trigonal pyramid (regular 3-sided pyramid) with bond angles of 107°.
Molecular geometry is the three-dimensional arrangement of the atoms that constitute a molecule. It includes the general shape of the molecule as well as bond lengths , bond angles , torsional angles and any other geometrical parameters that determine the position of each atom.
For example, NH 3 is a Lewis base, because it can donate its lone pair of electrons. Trimethylborane [(CH 3) 3 B] is a Lewis acid as it is capable of accepting a lone pair. In a Lewis adduct, the Lewis acid and base share an electron pair furnished by the Lewis base, forming a dative bond. [1]
NH2 or similar may refer to: Azanide (chemical formula NH − 2) Amino radical (chemical formula NH • 2) Nitrenium ion (chemical formula NH + 2) Primary amide group (chemical formula -NH 2) National Harbor–Alexandria Line (Route NH2), a WMATA bus line between Alexandria, Virginia and Prince George's County, Maryland; National Highway 2 (India)
Lewis structures do give some thought to the geometry of the molecule as oftentimes, the bonds are drawn at certain angles to represent the molecule in real life. Lewis structure is best used to calculate formal charges or how atoms bond to each other as both electrons and bonds are shown.
Molecular structure of ammonia and its three-dimensional shape. It has a net dipole moment of 1.484 D. Dot and cross structure of ammonia. The ammonia molecule has a trigonal pyramidal shape, as predicted by the valence shell electron pair repulsion theory (VSEPR theory) with an experimentally determined bond angle of 106.7°. [36]
[1]: 416 The geometry of the central atoms and their non-bonding electron pairs in turn determine the geometry of the larger whole molecule. The number of electron pairs in the valence shell of a central atom is determined after drawing the Lewis structure of the molecule, and expanding it to show all bonding groups and lone pairs of electrons.