chemistry

Question 1

what are ions?

Answer 1

atoms that have lost electrons (positive ions) or gained electrons (negetive ions)

Question 2

what are delocalised electrons

Answer 2

‘free’ electrons that are not associated with any single atom.

Question 3

physical properties of metals

Answer 3

particals packed closely together in a 3d grid arrangement called a lattice. Atoms in the lattice have lost their outer shell so th structure consists of metal ions in a sea/cloud of delocalised electrons. known as matallic bonding.

Question 4

how the stucture of a metal makes them conductive

Answer 4

the delocalised electrons are free to move throughout the lattice. this means that they can carry and electric current ( a flow of charge) so metals are good electrical conductors.

Question 5

what is malleable

Answer 5

metals can be hammered into shape

Question 6

what is ductile

Answer 6

can be drawn into wires

Question 7

why are group one metals reactive

Answer 7

they all have a single electron in their outer shell so they form ionic compounds containing 1+ ions.

the outer electrons move further away from the nucleus as you move down the group. this means that there is a weaker force of attraction between the negetive outer shell electron and the positive nucleus.

the outer elsectron lost is more easily is rubidium making it more reactive.

Question 8

transtion metals reactivity

Answer 8

much less reactive with oxegen than group one metals because of their is no reaction with dry air or oxegen free water.

Question 9

what is corrosion

Answer 9

the procces where metals react with substances in thre air to form oxides, carbonates, hydroxides or other compounds.

Question 10

exarmples of composite materials

Answer 10

concrete

fibreglass

carbon fibre

Question 11

exarmples of cermics

Answer 11

clay

glass

Question 12

what is a polymers?

Answer 12

are long chain of molecules made from reapeating monomer units.

some polymers have weak forces between the chains- this makes them softer and more flexible

while others have stong bonds holding the chains in a stronger and more rigid way.

Question 13

Properties of a HDPE

Answer 13

more rigid because of the higher density this is because it contains unbranched chains that can pack together more tightly

is used for bottles and other containers

Question 14

LDPE

Answer 14

weaker and more flexible because it has a lower density. this is because the chains are branched and therefore cannot pack together as easily