Physical Sciences Grade 11: Electrostatic Forces

Study Notes

Here are the study notes:

Chemical bonds are formed when atoms approach each other and the electrostatic forces of attraction and repulsion are balanced
A chemical bond exists when the attractive and repulsive forces are balanced
The "rule of two" states that a chemical bond involves the formation of electron pairs, known as a bonding pair

As atoms approach each other, the potential energy within the system decreases
At a critical point, the potential energy will be at its lowest when the electrostatic attractive and repulsive forces are balanced
This is when the combination is at its most stable
The distance between the nuclei of each atom is now fixed, known as the bond length

He atoms do not bond because they have a full valence shell and cannot undergo bond formation
Lewis diagrams can show combinations of different atoms
A lone pair is a pair of electrons that are not involved in chemical bonding
A bonding pair is a pair of electrons that are formed when a chemical bond is formed
Lone pairs do not make chemical bonds
The dative covalent bond is a special covalent bond formed from a lone pair

The dative covalent bond must be shown using NH₃⁺ and H₂O as examples
An atom with an empty valence shell is able to share a lone pair from another atom
The atom with the empty valence shell is usually a hydrogen atom
NH₃ and H₂O have lone pairs and are able to "share" a lone pair

Intermolecular forces are the forces of attraction and repulsion between atoms or ions within a chemical bond
There are three types of chemical bonds: covalent, ionic, and metallic

Chemical bonds within a chemical substance play a significant role in chemical and physical properties
There are different types of chemical bonds: covalent, ionic, and metallic
Covalent bonds occur between non-metal atoms through electron sharing
Ionic bonds occur between a metal atom and a non-metal atom through electron transfer
Metallic bonds occur between metal atoms through electrostatic forces of attraction

Molecules exist in three-dimensional space with different shapes depending on the arrangement of the atoms and number of bonds
This is explained through VSEPR theory
Repulsive forces exist between electron pairs that are present in the valence shells after bonding
These repulsive forces cause stress within the molecule, making electron pairs repel each other as far away as possible to minimize the stresses
Molecules wish to be in the lowest, most stable energy state

Ideal shapes are based on a central atom with no lone pairs surrounding them
There are five ideal shapes: linear, trigonal planar, tetrahedral, trigonal bipyramidal, and octahedral