Covalent Bonding Flashcards
What determines the melting and boiling point of a substance?
The strength of forces between particles
How does the strength of the force between particles affect the melting and boiling point of a substance?
The stronger, the force, the higher, the boiling point
How are covalent bonds formed
By atoms sharing electrons
Which type of atoms form covalent bonds between themselves
Non metal atoms
Two giant covalent substances
Graphite
Diamond
Silicon dioxide
Two small molecules
Water, carbon dioxide, oxygen, hydrogen ammonia, methane
Structure of bonding
Giant covalent
Billions of atoms bonded together by Strong covalent bonds
Structure and bonding of small molecules
Molecules made from atoms with strong covalent bonds between them between the molecules are weak into molecular forces
Structure and bonding inside a polymer
Lots of identical molecules joined together, with strong covalent bonds to form long chains between the chains a week intermolecular forces
Why do giant covalent substances have high melting points
It takes lots of energy to break the strong covalent bonds between atoms
Why do small molecules have low boiling points
Only a small amount of energy is needed to break the week inter molecular forces between molecules
Why do big molecules have higher melting points than small molecules
Intermolecular forces are stronger in big molecules
Why are most covalent substances not conductors of electricity
No charged particles that are free to move
Structure and bonding in graphite
Each carbon atom is bonded to three other carbon atoms to form a layer weak intermolecular forces between the layers. Delocalized electrons are free to move throughout the structure.
Structure and bonding in diamond
Billions of atoms joint together in a giant covalent network each carbon atom is joined to four other carbon atoms with strong covalent bonds no de localized electrons
