bonding, structure, properties of matter Flashcards
When a substance melts, what happens to the attractive forces between solid particles?
They are broken as particles break away from the solid lattice and become liquid particles.
What happens to the temperature when a substance melts?
Remains constant until all bonds are broken.
What happens to particles when liquid boils?
The particles overcome the attractive forces to become a gas.
What happens to the temperature when the liquid boils?
Remains constant until all attractive forces are overcome.
When are ions formed?
When metal atoms transfer their outer shell electrons to the outer shell of non-metal atoms. This electron transfer forms charged particles called ions.
The electrostatic force around each ion attract several opposite charged ions. What does his form?
A giant lattice.
Ionic compounds have (a) melting and boiling points because the ionic bonds are (b).
(a) high
(b) strong
Do all giant structures have a high melting and boiling point?
Yes, because they have lots of bonds to be broken.
Do ionic compounds have a better electrical conductivity of solid, or liquids?
Liquids, the ions can move around and carry the current whereas in solids they can’t.
Covlantely bonded substances can exist as…
Simple molecules, giant covalent structures, polymers.
The (a) forces increase as the molecular size (b), meaning the melting and boiling points (c).
(a) intermolecular
(b)increases
(c)increases
What is broken when a simple molecular force melts?
The weak intermolecular forces, not strong covalent bonds.
All of the (a) atoms in diamond, graphite and (b) are linked together by (c).
(a) carbon
(b) graphene
(c) strong covalent bonds
In diamond, each carbon atom is covalently bonded to how many other carbon atoms?
4.
Why does diamond have such a high melting/ boiling point?
It has strong covalent bonds in a giant structure.
Can diamond conduct in a liquid/ solid state?
No, there are no charged particles, free electrons to carry an electrical current.
How are carbon atoms structured in graphite?
In hexagonal rings, where each carbon atom is covalently bonded to 3 other carbon atoms, meaning each carbon atoms has a free electron to move around meaning graphite conducts both as a solid and liquid.
The covalent bonds in the layers are (a) but between layers there are only (b). These are (c) to break so the layers can (d) over eachother, making graphite soft and (e)
(a) strong
(b) weak intermolecular forces
(c) easy
(d) slide
(e) slippery
Does graphene have an identical structure to graphite?
It is identical to ONE layer of graphite, making it 1 atom thick. It has similar properties to graphite.
What is the smallest example of a spherical fullerene?
Buckminsterfullerene, which is a large but simple molecular substance.
What do buckminsterfullerene contain?
Mostly 6- carbon rings, but some 5- and 7-.
What can buckminsterfullerene be used for?
To trap drugs and deliver them to parts of the body, lubricants and catalysts.
Carbon nanotubes are (a), which have high length to diameter ratio. They have (b) between carbons in the layers, meaning they have (c) tensile strength. They are (d) conductors.
(a) cylindrical fullerenes
(b) strong covalent bonds
(c) high
(d) good
What are polymeres
Polymers are very large molecules which are made up of long chains of carbon atoms joined by strong covalent bonds. As the chains are long, the intermolecular forces between each chain are quire large, meaning polymers are solids.
Do metals form a giant lattice of positive metal ions in a sea of delocalised electrons?
Yes.
What is the electrostatic attraction between the positive ions and delocalised/ free electrons called?
A metallic bond.
Metallic bonds are usually (a) and need (b) of energy to overcome them, which is why most metals have (c) MP and BP.
(a) strong
(b) a lot
(c) high
Where do metallic bonds operate?
In pure metals and alloys.
The layers in metal ions can (a) eachother, meaning metals can be (b) meaning they are malleable and they can be (c) meaning they are ductile.
(a) slide over
(b) bent/ shaped
(c) drawn into wires
Are alloys a mixture of metals?
Yes, they are harder than pure metals too.
