Covalent Bonding Flashcards
What type of substances are covalent bonds formed with
non-metals
What are the factors that hold the atoms together when covalent bonds are formed
- The electrostatic forces of attraction between the nuclei of the two atoms
- The electrostatic forces of attraction between the shared pair of electrons.
Why does hydrogen form a molecule
Because an H2 molecule is more stable than separate atoms in the case of Hydrogen.
Why do substances with simple molecular structures have low melting and boiling points.
Although the substances have strong covalent bonds between atoms, the substances have weak and simple intermolecular bonds.
This means that only a little amount of energy is required to break these bonds. This means that the boiling and melting points will be lower.
Why does the boiling and melting point increase as the relative molecular mass increases.
Because as the relative molecular mass increases, the intermolecular bonds also increase in strength. This means that a higher amount of energy will be needed to break the intermolecular bonds as the relative molecular mass increases.
What are some of the physical properties of covalent compounds
- They do not conduct electricity because the atoms are held tightly in place by the electrostatic forces of attraction and are not free to move around.
- They are soluble in organic solvents.
- They are insoluble in water.
Why do large covalent structures have high melting and boiling points
Because large covalent structures are made from many non-metal atoms that have many covalent bonds. These covalent bonds are very strong, thus, they require a lot of energy to overcome the forces of attraction. This means that a high melting and boiling point with a high amount of energy is required to help atoms overcome the covalent bonds.
What are allotropes
These are different forms of the same element.
What are some allotropes of carbon
- Diamond
- Graphite
- C60 Fullerene
What are some properties of diamond
They are hard because the carbon atoms are bonded together by very strong covalent bonds, making them difficult to break
They do not conduct electricity because there are no free valence electrons because they are all held together very tightly in the covalent bond.
They have a very high melting and boiling point because the carbon atoms are bonded together by covalent bonds that require a large amount of energy to break, thus requires a large amount of energy.
It is arranged in a way such that each carbon atom is bonded to 4 other carbon atoms.
What are some of the uses of Diamond
- Cutting tools like drills
- Jewellery
What are some properties of graphite
The carbon atoms are arranged into layers and the forces of attraction between these layers are very small. This means that the layers can easily slide off.
Graphite also has a large melting and boiling point because the carbon atoms themselves are bonded together by covalent bonds. This means that they require a large amount of energy to overcome these bonds.
Graphite can also conduct electricity because only 3 electrons are bonded in the covalent bonds. The 4th electron is free to move and is delocalized, thus, Graphite can conduct electricity.
What some of the uses of Graphite
- As a lubricant
- In electrodes for electrolysis.
What are some of the properties of C60 Fullerene
They are soft and can easily be broken because the carbon atoms are bonded together by weak and simple intermolecular forces of attraction.
They also have a low melting and boiling point. This is because they have weak and simple intermolecular forces of attraction. This means that they require a lower amount of energy to break apart the bonds that hold them together.
They cannot conduct electricity because the 4th electron of each carbon atom can only go around each molecule and cannot jump around from molecule to molecule.
What are the uses of C60 Fullurene
- Drug delivery system in the body
- Lubricant
- Catalyst
