C3-Structure and bonding

Question 1

what are the properties of solids

Answer 1

Solids - fixed shape and volume with particles in a regular arrangement - they can’t be compressed. These can vibrate constantly

Question 2

what are properties of liquids

Answer 2

Liquids have a fixed volume but can flow and change shape - their particles have no structure but are all touching and can move past each other - they cannot be compressed

Question 3

what are properties of gases

Answer 3

Gases have no fixed shape or volume and can be compressed easily - their particles are very spaced apart - can move at high speeds in any direction

Question 4

what is the relationship between pressure and volume

Answer 4

Pressure and volume are inversely proportional - if you increase volume, pressure decreases and if you decrease volume, pressure increases

Question 5

how does solid go from solid to gas

Answer 5

When heating up a solid, the particles gain kinetic energy from the thermal energy and begin to vibrate. The particles vibrate so much that they become further apart, so the density of the substance decreases and it is now a liquid. The same thing happens from liquid to gas

Question 6

when heating something up why does temperature not change while change of state is happening

Answer 6

When heating something up, while a change of state is happening, the temperature of the substance does not increase as the thermal energy being provided is transferred into kinetic energy.

Question 7

substances with a higher melting or boiling point have a stronger or weaker force/bond?

Answer 7

Substances with a higher MP/BP have stronger forces/bonds between their particles

Question 8

define compound

Answer 8

A compound = two or more elements which are chemically combined

Question 9

what do atoms do to get a full outer electron

Answer 9

To get a full outer shell, these atoms either:
1)Transfer electrons
2)Share electrons

Question 10

what charge does an atom gain by gaining an electron

Answer 10

When an atom gains electrons it becomes negatively charged

Question 11

why does an atom gain a negative charge when gaining at electron

Answer 11

An atom has a neutral charge, and electrons have negative charges, so when a neutral atom gains negative electrons, it also becomes negatively charged

Question 12

what are the structures of ionic compounds

Answer 12

Ionic compounds are found in a giant ionic lattice
The very strong attractive electrostatic forces (ionic bonds) hold the ions in the lattice together very tightly

Question 13

why do ionic compounds have high melting/boiling points

Answer 13

So, it takes a lot of energy to break a lattice, so ionic compounds have a very high MP/BP

Question 14

Describe and explain if a solid ionic compound can conduct electricity:

Answer 14

Although it contains charged particles - the ions - they are trapped in place in the lattice by the ionic bonds. So, as they are unable to move, they can’t carry charge, so they cannot conduct electricity

Question 15

Describe and explain if a molten ionic compound can conduct electricity:

Answer 15

When you melt an ionic compound, it releases its ions, so the ions can carry charge, so the ionic compound can conduct electricity in its molten form

Question 16

Describe and explain if an aqueous ionic compound can conduct electricity:

Answer 16

When an ionic compound becomes an aqeous solution, its ions dissociate, so they are now free to move. As the ions can carry charge, this can conduct electricity

Question 17

what does covalent bonding mean

Answer 17

Covalent bonding = when non-metals react and their atoms share electrons

Question 18

what does molecule mean

Answer 18

Molecule = two or more non-metal atoms covalently bonded (the same atoms or different)

Question 19

what does ionic bonding mean

Answer 19

strong electrostatic forces of attraction between oppositely charged ions

Question 20

what produces positive charged ions

Answer 20

all metals

Question 21

what is the hardest natural substance and what is it made of

Answer 21

Diamond is the hardest known natural substance –> it is made up of lots of strong covalent bonds - and each carbon makes four covalent bonds

Question 22

what is the structure of diamond

Answer 22

Diamond is a giant covalent structure in a lattice form

Question 23

what are the properties of giant covalent structures

Answer 23

GCS Properties:
1)very high BP/MP (reasoning = covalent bonds)
2)Insoluble in water, Except graphite, they are hard and don’t conduct electricity

Question 24

what allows carbon to slip of

Answer 24

The weak intermolecular forces between the layers allows the layers to separate and slide off easily which is how it works in a pencil - the layers is what makes it soft

Question 25

howmany bonds does each carbon make in graphite and what effect does this have

Answer 25

In graphite, each carbon atom makes only 3 bonds (it can make 4)
As only 3 outer electrons are taken up in a bond, one electron from each carbon atom, becomes delocalised electron. As this can move and carry charge, graphite can conduct electricity

Question 26

why is graphite a good conductor of thermal energy

Answer 26

Graphite is also an excellent conductor of thermal energy –> the delocalised electrons move faster and rapidly transfer energy along the layers of graphite

Question 27

what does INTER MOLECULAR forces mean

Answer 27

INTER = between MOLECULAR= molecules - forces that arise between molecules (molecules are 2 or more same or different atoms covalently bonded together)

Question 28

what is Graphene

Answer 28

Graphene = a single layer of graphite (they discovered by sticking a piece of sellotape on graphite and pulling it off)

Question 28

what are properties of graphene
4 points

Answer 28

A better conductor of graphite
A very low density
Most reactive form of carbon
Pieces of graphene are extremely strong for its mass

Question 29

what are fullerenes

Answer 29

Fullerenes = large hollow cages made by C atoms joining

Question 30

what are the properties of fullerenes (2 points) and what can they be used for (3points)

Answer 30

Properties of fullerenes:
1)high tensile strenght –> used in reinforcing composite materials like in tennis rackets
2)high electrical conductivity –> used in electrical circuits

Fullerenes can be used for:
1)drug delivery into the body
2)lubricants
3)catalysts (due to the v v high SA:V)

Question 31

what are cylindrical fullerenes

Answer 31

Cylindrical fullerenes = carbon nanotubes –> really thin cylinders where the length is a lot bigger than the diameter

Question 32

what is the structure of metals

Answer 32

The atoms in a metal are built up layer on top of layer in a regular pattern
SO, this means that metals can form crystals

Question 32

what is galvanised steel

Answer 32

Galvanised steel = steel dipped into molten zinc (to prevent rusting)

Question 33

what is the attraction between in metallic bonding

Answer 33

In metallic bonding, there is attraction between the sea of delocalised electrons and the metal cations in the middle

Question 34

what are properties of metals

Answer 34

Properties of metals:
1)Metals are malleable (bent into shape) and they are ductile (drawn into wires) because the layers of regular, same-sized atoms slide over each other
2)Metals are very good conductors of heat AND electricity because The negatively charged delocalised electrons hold the metal cations in place by electrostatic forces of attraction
3)Metals have a high MP as it requires a lot of energy to overcome the electrostatic forces of attraction and separate the metal ions

Question 35

what is an alloy

Answer 35

Alloys = mixtures of metals (two different metal elements OR metal and non-metal (like carbon)

Question 36

what are cations and anions

Answer 36

Cations = positively charged ions
ANions = a Negatively charged ion