Chapter 1 - Covalent Structures

Question 1

What are the properties for giant covalent structures?

Answer 1

• Solids.
• They are joined together.
  They have large structures.
• The meting point depends on the energy.
• Insoluble
• Very hard

Question 2

Facts for Covalent bonding.

• Graphite is used for:
• Graphite is a (good/bad) conductor
• Graphite is very (hard/soft)
• What is an electrical current.
• The melting points for graphite and diamond are (high/low)
• Diamond and graphite are (metallic/non-metallic)
• Diamond is very (soft/hard)
• Diamond is a (poor/good) conductor
• Diamond is used for:
• How many bonds holds the carbon atoms together in graphite.
• What holds the layer of graphite together:
• In graphite what are the spare electrons in the carbon atom cable of doing.
• How are the atoms in covalent substances held together.
• Which element is both graphite and diamond made out of:
• What do both type of structure have:
• How many bonds does carbon atoms together in diamond.
• Why does graphite leave a mark when rubbed on paper.
• How is graphite able to conduct electricity?
• What makes graphite a good lubricant (reasons)
• Why do diamond and graphite have high boiling point.
• Why are diamonds are so hard?

Answer 2

• Pencils.
• Good.
• Soft.
• Is a flow of charge.
• High
• Non-metallic
• Hard
• Poor
• Jewellery
• 3
• The inter-molecular forces
• Conduct electricity
• They share electrons
• Carbon
• Lattice
• 4
• because the layers of graphite stays behind.
• Because they have delocalised electrons.
• It slides and doesn’t evaporate when you leave a mark.
• Because they are made out of carbon.
• They are hard substances because the intermolecular forces are very joint together.

Question 3

Type of structure:

Simple molecular and Giant covalent.

What are they made out of:

Diagram: (GOOD NOTES page 4)

Properties (characteristics)

Answer 3

Simple molecular structure:

Component: Made out of Carbon atoms
Diagram: (GOOD NOTES page 4)
Properties: At room temperature

Giant covalent bonding:

~Diamond

Component: Carbon atoms
Diagram: (GOOD NOTES page 4)
Properties: A solidified temperature, bad conductor (no delocalised electrons)

~Graphite

Component: Carbon atoms
Diagram: (GOOD NOTES page 4)
Properties: Solidified at room temperature, good conductor (delocalised electrons)

~Silica

Component: Silicon and oxygen
Diagram: (GOOD NOTES page 4)
Properties: solidified at room temperature, bad conductor (doesn’t have delocalised electrons)

Question 4

Nano technology

Some…

Positive:

Negative:

Answer 4

Positive:

Large surface area of volume ratio makes them effective catalysts.

Nanoparticles in sun creams can be absorbed easier than normal sun cream.

Negative:

Can damage the lungs

So small tat can enter the blood stream

Question 5

• What type of bonding do pure metals have.
• Why do metals have a high melting point and boiling points.
• Why are metals are good electrical conductors.

Answer 5

• Metallic bonding
• They have a high and boiling points because the particles in a solid are very close to each other.
• They are good conductors because they vibrate so it creates heat and friction and that conducts electricity.

Question 6

What is an alloy? (GOOD NOTES page 10)

Answer 6

An alloy is a mixture of metals, an alloy is harder to bend because the rows of atoms can’t slide in comparison with the pure metals that can slide, this means that pure metals can bend easier than alloys.

Question 7

Explain the definitions for the following

• Molten:
• Disoleved:
• Solid:

Answer 7

Molten: Electrons that vibrate they can conduct electricity.

Dissolved: The atoms are separate to each other so it can not conduct electricity.

Solid: The atoms are separate to each other so it can not conduct electricity.