OG unit 1.5

Question 1

How are the crystal coordination numbers defined?

Answer 1

Number of nearest ions to each other ions + vice versa

Question 2

How to say the crystal structure for sodium chloride?

Answer 2

6 ions around each other ion therefore it has a 6.6 coordination

Question 3

What’s the name for sodium chloride’s crystal structure?

Answer 3

[interlocking?] face? centre cubic

Question 4

Why is caesium chloride’s structure called body-centred cubic? (bcc)

Answer 4

Well in the cube, there’s one singular caesium ion and each corner of the cube consists of chloride

Question 5

What does sodium chloride + caesium chloride have in common?
(structure and bonding)

Answer 5

It’s said to be giant and the bonding is ionic

Question 6

What’s the melting point for strong ionic bonds?

Answer 6

Lot’s of heat req. = very high mp

Strong force of attraction between oppositely charged ions

Question 7

What’s the conductivity for strong ionic bonds?

Answer 7

Zero as the solid ions fixed in a lattice.
However they can conduct if molten/dissolved in water as ions free to move + carry current

Question 8

What’s the hardness for strong ionic bonds?

Answer 8

Hard but brittle. Can be cleaved easily (breaks crystal lattices)

Question 9

Define allotrope

Answer 9

Different forms of the same chemical element

Question 10

Properties of Graphite?
(6 things)

Answer 10

• High m.p, lots of heat req to break covalent bonds
• 4 valence (outer most shell) what da frick does that mean
• 3/4 e- used in bonding
• 1 free e- to move (delocalised) + carry electrical current
• Hexagonal layers of carbons connected to 3 other carbons by strong covalent bonds
• Layers held together by weak intermolecular forces that can easily be overcome = layers slide off easily past each other

Question 11

Use of Graphite and why?

Answer 11

Lubricants and pencils
Cuz it’s slippery and soft

Question 12

1 thing in common of diamond and graphite?

Answer 12

Very high mp due to very strong covalent bonds

Question 13

What structure and bonding of diamond + graphite?

Answer 13

The structures are said to be giant and the bonding is covalent

Question 14

Properties of Diamond?
(Only 3 things)

Answer 14

Technically similar to graphite but wayy stronger because:
- Each carbon atom bonded to 4 others, forming 3-dimensional structure (a tetrahedral structure)
- Has stronger intramolecular bonds = more energy req to overcome bonds
- 0 electrical conductivity compared to graphite cuz no free e- to carry the current

Question 15

Use of diamond and why?

Answer 15

Drill bit cuz like
it’s rlly strong

Question 16

wat 3 other forms of carbon?

Answer 16

• Buckminsterfullerene
• Graphene
• Carbon nanotubes

This may be needed im not sure but if it is in there, just know u have failed miserably

Question 17

What happens when iodine is heated?

Answer 17

Turns into gas
(was this rlly needed? welp the more u know)

Question 18

What type of structure is iodine? and why it got strange property of it to turn into gas or something like that?

Answer 18

• Face-centred cubic
• Has weak VDW forces

Question 19

Explain ice’s structure or summin like that
(3 things)

Answer 19

• Hydrogen bonds between water molecules hold them together
• In a fairly open tetrahedral structure
• Strong bonds within the water molecules are polar covalent

Question 20

What’s the ‘electron sea’ model for bonding in metals?

Answer 20

That lattice drawing thingy majiggy:

• Neat rows of positive metal ions
• Electrons free to move (delocalised) and carry on electric current

Question 21

What structure and bonding of them metals?

Answer 21

Giant, metallic

Question 22

How can metals differ?

Answer 22

Different number of ion charges = different number of delocalised electrons

Question 23

How do metals conduct electricity?

Answer 23

• Plenty of delocalised electrons
• Free to move and carry current

Question 24

How does metal have high melting & boiling points?

Answer 24

• Strong electrostatic attraction
• Between oppositely charged particles

(ion + electron = metallic bonds)
^ idk, this was in the book

Question 25

Define malleable?

Answer 25

Easily shaped

Question 26

Define ductile?

Answer 26

Easily stretched into wires or summin?

Question 27

How can metals exhibit malleable/ductile properties?

Answer 27

• Arranged in neat rows (bonding)
• Can easily slide past each other

Question 28

Properties of giant ionic compounds (such as the chlorides)?

Just do last 4

Answer 28

Generally:
- Hard
- Brittle
- High mp due to strong ionic bonds

• No electrical conductivity in solid state, ions fixed in position
• Conducts when molten/aqueous solutions (ions free to move and carry electric current)
• Can sometimes not be solube in water depending on energetics/chemical reaction factors, but most ionic chlorides are soluble

Question 29

2 giant covalent compounds?
and 1 new info

Answer 29

Diamond and graphite

• Insoluble in water

Question 30

Info of simple covalent compounds? (iodine)

Answer 30

• Doesn’t conduct electricity (no free electrons)
• Soft and volatile (easily evaporated) due to iodine molecules held together by weak Van de Waal’s forces

Question 31

Additional info of metallic bonding?
(only do last 2)

Answer 31

Delocalised electrons:
- Allow to conduct an electrical current
- Allows good thermal conductivity

• Melting temp & hardness increases
• With number of electrons per atom involved with bonding

Question 32

Lastly, it’s all about gathering questions to respond to

Answer 32

Alright