Covalent Bonding Flashcards
How is a covalent bond formed?
Sharing pairs of electrons with other atoms
Definition of covalent bonding
Strong electrostatic attraction between negatively charged shared electrons (bonding pair) and the positively charged nuclei of the atoms involved
Why do simple molecular structures have low melting and boiling points
Intermolecular Forces between the molecules are very weak so the molecules are easily separated
Why are the melting and boiling points of simple molecular structures higher with a high relative molecular mass?
The intermolecular forces are stronger because there’s more points along the larger molecules for the intermolecular forces to act between them, there’s more energy needed to break the forces.
Why are giant covalent structures solids with very high boiling points
There are lots of strong covalent bonds so it takes a lot of energy to break them up
How does the structure of diamond influence its properties?
High melting point - strong covalent bonds as it is made of carbon atoms, takes a lot of energy to break
Hard - Strong covalent bonds hold the atoms in a rigid lattice structure
Doesn’t conduct electricity - no free electrons or ions
How does the structure of graphite influence its properties?
Soft and slippery - Carbon atom only forms 3 covalent bonds, creates layers which are help together weakly by intermolecular forces so are free to slide over each other
High melting point - Strong covalent bonds need loads of energy to break
Conducts electricity - Delocalised electrons, is free and can move therefore conduct electricity
How does the structure of C60 Fullerene influence its properties?
Soft - molecules are only held together by intermolecular forces, no covalent bonds
Poor conductor of electricity - delocalised electron but cannot move between molecules
Solid at room temperature - molecules are large, intermolecular forces between the molecules are strong, doesnt change state very easily
