C3 Flashcards
Do all particles vibrate?
No just solids
Where is energy transferred from in melting and boiling?
From the surroundings
Where do particles go to in freezing and condensing?
From the substance to the surroundings
Qualities of solids
A fixed shape or volume that can’t be compressed
Qualities of liquids
Fixed volume but can flow and move, occupying more space from when solid
Qualities of gases
No fixed shape or volume, can be compressed easily
Draw the three states
Refer to the textbook
What do elements react together to make?
Compounds, which have gained or lost electrons
Which groups react with each other forming ionic bonds
Group 1, Group 7
Group 2, Group 6
Group 3, Group 5
What is ionic bonding
A strong electrostatic force of attraction between these oppositely charged ions
Why do ionic bonding have high melting points?
Because it takes a lot of energy to break the strong ionic bond , operating in all directions, that hold a giant ionic lattice together.
What state are ions at room temp?
Solids
When can ions conduct electricity and why?
Ionic compounds will conduct electricity when molten or dissolved in water because of the ions becoming mobile and able to move in water. They will then have delocalised electrons.
What holds ions together in a giant ionic lattice?
Strong electrostatic forces called ionic bonds
When are covalent bonds formed?
When atoms of non-metals share pairs of electrons with each other
What do substances containing covalent bonds consist of?
Simple molecules for most but some have giant covalent structures
Are covalent bonds strong?
Yes because they share electrons
What are substances made of simple molecules melting and boiling point like?
Lowww
Are the forces between simple molecules weak?
Yes because of weak intermolecular forces
Why can simple molecules not carry charge ?
Because they have no overall charge so they can’t carry it so they don’t conduct electricity
Give 3 examples of giant covalent structures
Diamond, graphite and graphene
Facts about diamonds
Ever C atom is joined to 4 other C atoms. 3d shape. Very strong bonding, making it hard to break, boil and melt. No ions, no free delocalised electrons, no conduction
Facts about graphite
Every C atom is joined to 3 other C atoms forming a flat plate of hexagons, lying in layers. High melting and boiling points because if strong bond, weak intermolecular forces. Delocalised electron for every C atom so it conducts
Facts about graphene
1 layer of graphite, if it is rolled up it is called a nano tube
What can fullerenes form?
Large cage-like structures and tubes, based on hexagonal rings of carbon atoms
What are fullerenes useful for?
Transport mechanism for drugs to specific places in the body, as catalysts and as reinforcement for composite materials
What are Buckyballs?
C60, football shape, can’t conduct, very strong
What is metallic bonding?
Positively charged metal ions, which are held together by electrons from the outermost shell of each metal ion, the delocalised electrons are free to move in the giant metallic lattice so it conducts
What is 1 nanometer equal to?
1x10^-9m
What is nano science?
The study of small particles between 1 and 100 nano meters in length
What is good about nano particles?
The surface area in relation to volume is extremely good
What is a micrometer?
1x10^-6 m
What can nanoparticles be used for?
Sunscreen, carrying drugs around the body, catalysts and cosmetics
What does the particle theory describe?
The movement of particles and the average distance between them.
What are the limitations of the particle model?
They assume that particles are made up of solid spheres with no forces acting between each other. However as atoms come in different sizes and shapes, cause reactions between each other and the fact they are mostly empty space it can be proved wrong.
How can atoms become ions?
Through sharing electrons which is covalent bonding or transferring electrons which is ionic bonding.
When are covalent bonds formed?
When atoms of non-metals share pairs of electrons with each other.
What are polymers?
They are made of small reactive molecules that bond to each other to form long chains.
What is an alloy and why are they used?
A mixture of metals. They are used for making the atoms a different size to each other so that it makes it harder for the layers to slide over each other so they are harder than pure metals.
What are the possible risks of nano-particles?
A spark could cause an explosion due to them being catalysts. They could find their way into the atmosphere and could cause health hazards.
