Covalent Bonding Flashcards
What is a single covalent bond?
When one pair of electrons is shared between each other.
What is a molecule?
Two or more atoms covalently bonded together.
What is a diatomic bond?
A bond between two atoms.
Why do covalent bonds have strong forces of electrostatic attraction?
This is because both atoms involved have an electrostatic attraction to the electrons being shared.
What is a molecule of an element?
A molecule is a chemical bond between two atoms. A molecule of an element is when that bond is made up of atoms from the same element, e.g. two carbon atoms.
What are simple covalent/molecular covalent structures?
Within each molecule of a molecular covalent structure the atoms are joined by strong covalent bonds. Since the molecules are not charged, the individual molecules are not joined together strongly. (Weak Van der Waals’ forces)
What happens to Van der Waals’ forces when turned into molten?
The Van der Waals’ forces break apart, but the strong covalent bonds remain.
What is an example of a structural formula of a covalent bond?
H-H
What is an example of a molecular formula of a covalent bond?
H2
What are giant molecular covalent structures?
Molecules containing millions of atoms. Examples: Diamond, graphite, graphene.
Examples of allotropes, i.e. what are they?
Allotropes are different forms of the same element. E.g. diamond, graphite and graphene are all made of carbon but have different structures.
What are the arrangements of diamond, graphite and graphene in order?
Diamond: Tetrahedral arrangement
Graphite: Hexagonal rings with weak forces of attraction between layers.
Graphene: One layer. Toughest material in the world, conducts electricity and heat, high melting point.
What are the properties and uses of diamond, graphite and graphene?
All have high melting points
All insoluble
Diamond doesn’t conduct as it has no delocalised electrons (one electron is connected to 4) Graphene and Graphite do.
Diamond is hard, graphite is soft due to sliding layers due to weak forces between layers, graphene is strong as it has strong bonds.
Use: Diamond is used for cutting tools/drill bits, graphite=lubricants for machinery and pencil leads and graphene is used for solar cells and batteries.
