Chemistry deals with the way in which sub atomic particles bond together to form atoms. Chemistry also focuses on the way in which atoms bond together to form molecules. In the atomic structure, electrons orbit the atomic nucleus in what are called orbitals. Each orbital shell can hold a certain number of electrons. When the nearest orbital shell is full, new electrons start to gather in the next orbital shell out from the nucleus, and continue until that shell is also full. The collection of electrons continues in ever widening orbital shells as larger atoms have more electrons than smaller atoms. When 2 atoms bond to form a molecule, their electrons bond them together by mixing into openings in each others' orbital shells. As with the collection of electrons by the atom, the formation of bonds by the molecule will start at the nearest available orbital shell opening and expand outward from there. Use these tips to learn how to calculate bond order in chemistry.
Method 1 of 2: Determine Bonding and Antibonding Orbitals
1Consult a diagram of electron orbital shells. These are available in chemistry textbooks and presentations. Note that each shell lies further and further out from the nucleus of the atom. As energy always seeks the lowest possible state (a property known as entropy), the electrons will seek to populate the lowest orbital shells available.Ad
2Understand the concept of bonding orbitals. When 2 atoms attempt to form a molecule, they seek to use each others electrons to fill the lowest possible states in the electron orbital shells. By noting how full the orbital shells of each atom are, it can be determined how many of the electrons in higher energy states will be able to fill the more stable lower energy state shells of the other atom. These are referred to as bonding orbitals.
3Grasp the concept of antibonding orbitals. When the 2 atoms attempt to form a molecule by sharing electrons, some electrons will actually be driven to higher energy state orbital shells because the lower energy state orbital shells become filled. These are referred to as antibonding orbitals.
Method 2 of 2: Calculate Bond Order
1Determine the new energy state of the compound being formed. Each electron that entered a bonding molecular orbital will act to stabilize the new molecule. Each electron that entered an antibonding molecular orbital will act to destabilize the new molecule. Use the equation 1/2 of (electrons in bonding molecular orbits minus electrons in antibonding molecular orbits) to determine the new energy state.
2Note the new energy state as the bond order of the molecule. If the bond order is zero, the molecule cannot form. The higher bond orders indicate greater stability for the new molecule.
3Try a simple example. Hydrogen atoms have 1 electron in the s shell. The s shell is capable of holding 2 electrons. When 2 hydrogen atoms join, each completes the s shell of the other and 2 bonding orbitals are formed. No electrons are forced to move to the next higher orbital, which is the p shell, so no antibonding orbitals are formed. The bonding order is thus (2-0)/2 or 1. This forms the common molecule H2, commonly known as hydrogen gas.Ad
We could really use your help!
In other languages:
Español: Cómo calcular el orden de enlace en química, Italiano: Come Calcolare in Chimica l'Ordine di Legame, Русский: рассчитать кратность связи в химии, Português: Como Calcular a Ordem de Ligação em Química
Thanks to all authors for creating a page that has been read 108,193 times.