Covalent Bonding Flashcards
(26 cards)
What is covalent bonding?
Atoms can share or transfer electrons to form strong chemical bonds.
What is a covalent bond?
A covalent bond is when electrons are shared between non-metal atoms.
What determines the number of electrons shared in a covalent bond?
The number of extra electrons an atom needs to make a full outer shell.
What are the three states of matter represented in the particle model?
Solid, liquid, gas.
What assumptions does the particle model make?
- There are no forces between the particles
- All particles in a substance are spherical
- The spheres are solid.
What affects the amount of energy needed to change the state of a substance?
The forces between the particles.
What is a single covalent bond?
Each atom shares one pair of electrons.
What is a double covalent bond?
Each atom shares two pairs of electrons.
What are the three main types of covalent structures?
- Giant covalent
- Small molecules
- Large molecules.
What characterizes giant covalent structures?
They contain many billions of atoms, each bonded strongly to a number of others.
What is an example of a giant covalent structure?
Diamond.
What characterizes small molecules in covalent structures?
They contain only a few atoms with strong covalent bonds between them.
What are polymers?
Large molecules made of many repeating units joined by covalent bonds.
What are the melting and boiling points of giant covalent substances?
High melting and boiling points due to strong covalent bonds.
What are the melting and boiling points of small molecules?
Low melting and boiling points because only intermolecular forces need to be overcome.
What is the typical state of large molecules at room temperature?
Normally solid.
Why do most covalent structures not conduct electricity?
They do not have delocalised electrons or ions that are free to move.
What is unique about graphite compared to other giant covalent structures?
It has layers that can slide over each other due to weak intermolecular forces.
What are fullerenes?
Hollow cages of carbon atoms bonded together in one molecule.
What is Buckminsterfullerene?
The first fullerene discovered, consisting of 60 carbon atoms.
How do the carbon atoms in nanotubes arrange?
In cylindrical tubes.
What enables graphite to conduct electricity?
Delocalised electrons that are free to move.
What is graphene?
A single layer of graphite with strong covalent bonds.
What potential applications does graphene have?
Use in composites and high-tech electronics.
