topic 2

Question 1

what is ionic bonding.

Answer 1

the electrostatic attraction between negative and positive ions.

Question 2

what can ionic compounds from

Answer 2

giant lattice structures

Question 3

describe the properties of ionic compounds

Answer 3

-high melting and boiling
-cannot conduct electricity when solid,but can when dissolved in liquid or melted
-this is because the ions in a solid are fixed but in a liquid they can move and carry a charge

Question 4

how are ioinic compounds held together

Answer 4

held in a giant lattice
electrostatic attraction between positive and negative ions hold structure together

Question 5

how are ionic compounds formed

Answer 5

when a non metal and metal react

Question 6

what is a covalent bond

Answer 6

shared pair of electrons between 2 atoms

Question 7

describe the properties of simple molecular covalent substances

Answer 7

strong covalent bonds
weak intermolecular forces
low melting and boiling
cannot conduct electricity as no ions
liquid and gas

Question 8

describe the properties of giant covalent structures

Answer 8

-high melting and boiling
-cannot conduct electricty exxcept for graphite
-solids

Question 9

describe the properties of diamond and graphite

Answer 9

diamond- high melting and boiling
-hard
-cannot conduct electricty as theres no free electrons to carry charge
-4 covalent bonds for each atom
graphite-3 covalent bonds for each atom
-this means each carbon atom has 1 spare electron which is free to move around and carry a charge(deloclaised)
-this therefore means graphite can conduct electricty
-soft and slippery, hexagonal layers with no covalent bonds between them, this means they can slide over each other

Question 10

describe the properties of fullerene

Answer 10

nanotubes- high strength to weight ratio, can be used to strnegthen materials,used in nanotechnology,used in electronics as they have delocalised electrons
buckminsterfullerene-hollow sphere,60 carbon atoms, form rings with 5 or 6 carbon atoms, can be used as lubricants, catalsyst,deliver drugs in body

Question 11

describe polymers

Answer 11

polymers are made by joining small identical molecules
-strong intermolecular forces, high melting and boiling.
-solids at room temp

Question 12

describe metallic bonding

Answer 12

metallic bonding is the electrostatic attraction between non metals
-high meltimg and boiling, malleable
-electrons in outer shell of each atom are delocalised, this makes the metal atom have a positive charge. there is electrostatic attraction between the electrons and the atoms holiding the structure in place.
-they are malleable because the layers can slide over each other.

Question 13

what are alloys

Answer 13

alloys are mixtures of metals that have different sized atoms, these different sized atoms can disrupt the regular structre, making it harder for the layers to slide over each other