Covalent Bonding Flashcards
What is covalent bonding?
Covalent bonding is the bond formed through the sharing of electrons.
OR
Covalent bonding is the attraction between the shared electrons and the adjacent nuclei
What structures do covalent compounds form?
They can form Giant covalent structures or simple molecular structures.
What are the limitations of using 2D drawings or 3D structures to represent Giant covalent structures?
Pure giant covalent structures have an infinite amount of particles, and can’t be shown accurately using a model/drawing.
(In real life, the giant covalent structures just bond with other substances on the outside of the structure so they don’t actually go on forever)
Why do simple molecular structures have low melting and boiling points?
They have low melting and boiling points because the weak intermolecular forces that join the molecules together don’t need much force to break.
What is a giant covalent structure?
When atoms bond with one another on a large scale, involving huge but variable amounts of atoms.
What is a simple molecular structure?
When a few atoms bond together to create molecules, and then the individual molecules are held together by weak intermolecular forces.
Why do simple molecular structures not conduct electricity?
They don’t conduct electricity because there are no free flowing electrons or ions.
What are the general properties of substances with giant molecular (covalent) structures?
- solid at room temperature
- high melting/boiling points
- cannot conduct electricity
- insoluble in water
Why is diamond hard and graphite slippery?
Diamond is hard because of the very many very strong covalent bonds. These take a lot of force to break, so diamond is very hard.
Graphite is slippery however, because its structure is in layers, which, due to weak intermolecular forces, can slide over each other easily.
Why can graphite conduct electricity and thermal energy?
Graphite can conduct electricity and thermal energy because it has a free electron moving between layers.
What structure does SiO2, silicon dioxide or silica, have?
Giant covalent
What is the structure of fullerenes?
Fullerenes are molecules of carbon atoms with hollow shapes. Their structures are based on hexagonal rings of carbon atoms joined by covalent bonds.
What is the structure of graphene?
It is a single layer of graphene
What are some uses for fullerenes?
Lubricants and catalysts.
