Bonding, Structure And The Properties Of Matter Flashcards
What’s it called when a gas becomes a solid? - Properties of Matter
Sublimation
What is the relationship between melting point, boiling point and forces between particles? - Properties of Matter
The stronger the forces between particles, the more energy is required to break bonds
What structure does an ionic compound have? S+B
They form a regular ionic lattice, as the positive and negative ions are attracted to one another.
How is an ionic lattice held together? S+B
Strong electrostatic forces of attraction
What limitations are there to 2-D and 3-D ionic models? S+B
2-D: only shows ionic arrangements in 1 layer
3-D: presents lots of space between ions which there isn’t
How do ionic lattices melt and boil? - S+B
Energy must be transferred to an ionic substance (in the form of thermal) in order to overcome the electrostatic attraction between ions. The more energy needed, the higher the melting/boiling point
A substance can conduct electricity when? - S+B
If they contain charged particles (ions or electrons) which are free to move
When can ionic substances conduct electricity? - S+B
When it has melted into a liquid or is molten or is dissolved in an aqueous solution
How big are atoms? - S+B
-10
1x10
What diagrams shows how covalent bonding takes place? - S+B
Dot + cross diagrams, structural formula (lines showing the no. of bonds)
What are the forces like between molecules of intermolecular forces?
Weak, don’t require much energy to break
What are giant covalent substances? - S+B
A substance which contains many atoms joined by covalent bonds
What type of boiling + melting points do giant covalent substances have? S+B
They are solid at room temp, and therefore have high melting and boiling points
Can giant covalent substances conduct electricity (+ name exception) - S+B
Most giant covalent substances cannot carry charge as they have no free charged particles. Graphite is an exception as it has delocalised electrons.
What element are both diamond and graphite made from? - S+B
Carbon
How many carbon atoms is a carbon atom bonded to in diamond and graphite? - S+B
Graphite - every C is bonded to 3 C
Diamond - every C is bonded to 4 C
What does graphite’s 3 bond structure mean can happen? - S+B
Graphite can carry electrical charge as it has one delocalised electron from each atom.
Why is graphite slippery? - S+B
It has layers which fit over the top of one another. The forces between layers are weak, and can therefore be used as a lubricant
What are fullerenes + 2 examples? - S+B
Fullerenes are carbon molecules that are hexagonal
Nanotubes and buckminsterfullerenes
What are nanotubes used for and why are they ideal for this? - S+B
Useful in electronics and nanotechnology due to their strength and their ability to conduct electricity
What is a polymer? - S+B
A large molecule formed from many identical smaller molecules known as monomers
What properties do polymers have? (IM Forces) - S+B
Strong IM Forces, mean polymers melt at high temperatures than smaller molecules. Solids at room temp
Describe metallic bonding - S+B
Atoms are arranged regularly, with each atom relinquishing electrons from their outer shells, which are delocalised and allow metals to carry charge
What is the term for the outer electrons in metallic bonds? - S+B
The sea of delocalised electrons
What properties do metals have? - S+B
Good electrical conductors due to delocalised electrons, also good thermal conductors. High melting + boiling due to strong bonding
Why are alloys stronger than pure metals? - S+B
Different sized atoms disrupt the smooth, regular structure of the metal, making it harder
When covalently bonded structures are heated, what is broken in the structure? - S+B
The intermolecular forces are broken, not the bonds between atoms
What is the size of a nanoparticle? - S+B.
1x10^-9 metres