Molecular Geometry by Grace

What is molecular geometry and what are the common molecular shapes?

Molecular geometry is the three dimensional representation of atoms making up a molecule. This geometry determines the properties of a substance, such as reactivity, polarity, phase of matter, color, magnetism, and biological activity. Angles between bonds on an atom depends on the strength of the bonds on a molecule.

It can be determined by spectroscopic and diffraction methods. Microwave and Raman spectroscopy can give information about molecular geometry. Molecular geometries can be, determined best at low and high temperatures. There are many common geometries, such as Linear, Trigonal planar, Tetrahedral, Pyramidal, and Bent.

Linear molecular geometries have angles of 180 degrees. It exists in a straight line and is is between two adjacent bonds. A common example is carbon dioxide and nitric oxide.

Trigonal planar molecular geometries have angles of 120 degrees. The molecules are somewhat triangular and flat. An example is boron trifluoride.

Tetrahedral molecules are have four bonds on one central atom and do not have any unshared electron pairs. The angles are 109.5 degrees with a common example being methane.

Pyramidal molecular shapes are pyramid like. They have triangle like bases and angles of about 107 degrees. Ammonia is a common example of this.

Bent molecules have angles of about 104.5 degrees. They have a non-linear shape and two pairs of bonded electrons. Water is a good example of this molecule shape.

Molecules come in many different types of shapes. These molecules come in different dimensions and vary in angle size, polarity, and other properties.

Note from Ms. Raino: The students got to sign up for the date they wanted- the reason you are seeing so much of Grace is because she believes in getting assignments done, and out of the way.