C2-Structure and bonding Flashcards
What are some limitations of the particle model of matter?
The particles in substances can vary in size, aren’t spherical and molecules and ions can distort their shapes
What type of bonding bonds a metal and a non metal?
Ionic bonding
Explain the process of ionic bonding
- A metal donates an electron(s) to a non-metal to accomplish a full outer shell for both elements
- The metal becomes a positive ion
- The non-metal becomes a negative ion
- The opposite electrostatic charges attract
What ions do the following groups form in ionic bonding:
1)Group 1?
2)Group 2?
3)Group 3?
4)Group 4?
5)Group 5?
6)Group 6?
7)Group 7?
8)Group 8?
1)1+
2)2+
3)3+
4)don’t form ions apart from tin or lead
5)3-
6)2-
7)1-
8)don’t form ions
What does ionic bonding form?
Salts
What are some properties of giant ionic lattices
- High melting point (solids at room temperature)
- Can conduct electricity when molten or dissolved in water due to the ions being mobile through the liquid
- Strong
What are cations?
Positive ions-metals
What are anions?
Negative ions-non metals
What type of bonding bonds 2 or more non-metals?
Covalent bonding
What is covalent bonding?
Where atoms of non-metals share pairs of electrons with each other in order to gain a full outer shell of electrons
What are the properties of simple molecules covalently bonded?
- Weak intermolecular forces-low boiling points
- Very strong intramolecular forces
- Liquid/gas at room temperature
- Can’t conduct electricity
What are the properties of giant covalent structures?
- Strong intermolecular forces-high boiling points
- Very strong intramolecular forces
- Solid at room temperature
- Can conduct electricity in some cases
What is an allotrope?
2 or more physical forms in which an element can exist-such as for carbon being able to make diamond and graphite
What are some examples of giant covalent structures?
- Diamond
- Graphite
- Graphene
- Carbon nanotubes
- Buckminsterfullerine
- Silicon dioxide
What giant covalent structures are electrical conductors and why?
Graphite, Graphene and Carbon nanotubes can conduct electricity as they are only covalently bonded 3x so have leftover delocalised electrons
Why is graphite so soft?
The layers of graphene can slide past each other
What is the chemical formula of buckminsterfullerene?
C₆₀
Why are fullerenes useful?
They are useful as catalysts, transport mechanism for drugs and as reinforcement for composite materials
Why is graphene useful in the electronics industry?
It is an electrical conducter and is also flexible meaning that it can be used in foldable phones
What type of bonding bonds metals?
Metallic bonding
How does metallic bonding work?
The metal atoms are arranged in a regular pattern in a giant metal lattice. The electrons in the outer shell become delocalised and form a sea of constantly moving electrons. There is electrostatic attraction between the positive metal ions and the electrons
Explain why metals conduct electricity and heat well
Their delocalised electrons transfer charge and energy well
Explain why metals are ductile
As the metal layers can slide past each other but are still held together by the delocalised electrons
Why are nano-particles able to react much more quickly?
They have a higher surface area to volume ratio
What is nanoscience?
The study of particles between 1 and 100 nanometres in size
How large is a nanometre?
10⁻⁹ m
What is the size of a fine particle?
100-2500nm
What is the size of a coarse particle?
2500-10,000nm
Why are nanoparticles good for industrial processes?
Less of them will need to be used-they are better catalysts
What are polymers made up of?
Chains of monomers
What are some uses of nanoparticulate materials?
- medical treatments
- cosmetics, deodorants and sunscreens
- electronics
- catalysts
What are some possible risks to nanoparticles?
- They could be dangerous if reacting with some fuel
- They can enter the human body and catalyse unwanted reactions
- They can harm aquatic life
