2.1-2.9

Question 1

define ionic bond

Answer 1

the electrostatic attraction between oppositely charged ions. mostly happens between metals and non-metals

Question 2

what are the 6 main molecular ions?

Answer 2

hydroxide: OH^-
nitrate NO3 ^-
sulphate: SO4 ^2-
Carbonate: CO3 ^2-
hydrogen carbonate: HCO3 ^-
Ammonium: NH4 ^+
Phosphate- PO4 ^3-

Question 3

how to draw a dot and cross diagram for ionic compounds

Answer 3

the symbol goes in the centre,
draw the outer shell with dots and crosses
put in a bracket with the charge by the top right corner
and the ratio number next to the bottom right corner

Question 4

define: coordination number

Answer 4

the number of oppositely charged ions surrounding one ion in an ionic lattice structure

Question 5

explain the M.P of ionic compounds

Answer 5

they have strong electrostatic forces of attraction which require lots of energy to break.

Question 6

explain the strength of ionic compounds

Answer 6

they are very brittle. any dislocation causes alike charges to be next to each other. these repel causing a fracture

Question 7

explain the solubility of ionic compounds

Answer 7

only soluble in polar solvents. Solubility depends on the balance between the attraction of the oppositely charged ions to each other and the attraction of the separate ions to the solvent

Question 8

explain the conductivity of ionic compounds

Answer 8

only conductive when aqueous of molten. the ions need to be free to move but they are stuck in place when solid

Question 9

define covalent bond

Answer 9

the electrostatic force of attraction between the nucleus and the shared pair of electrons. only happens between non-metals

Question 10

define hybridisation

Answer 10

when atoms move electrons to an unoccupied orbital in the same energy level to form more covalent bonds

Question 11

what is a dative covalent bond?

Answer 11

when one atom donates both electrons in a covalent bond.

Question 12

explain the m.p of simple molecules

Answer 12

it intermolecular forces are weak so very little energy is needed to separate the molecules

Question 13

explain the conductivity of simple molecules

Answer 13

they don’t conduct electricity because there are no free ions or electrons

Question 14

explain the solubility of simple molecules

Answer 14

depends on the polarity. tend not to be soluble in water

Question 15

define electronegativity

Answer 15

a measure of the attraction between a bonded atom and the pair of electrons in the covalent bond

Question 16

factors affecting electronegativity

Answer 16

nuclear charge- higher charge causes a stronger
attraction
atomic radius- closer to the nucleus causes a stronger
attraction
shielding- more shielding causes more repulsion so
the attraction is weaker

Question 17

how does electronegativity change down a group and why

Answer 17

it decreases. the atomic radius and shielding increases. this causes a weaker attraction to the bonding electrons

Question 18

how does electronegativity change across a period

Answer 18

it increases. the atomic radius decreases and the nuclear charge increases. this causes a stronger attraction to the bonding electrons.

Question 19

whats a metallic bond

Answer 19

the electrostatic force of attraction between metal cations and a sea of delocalised electrons.

Question 20

explain the density of metals

Answer 20

they have a higher density. this is because the cations are packed together tightly

Question 21

explain the M.P of metals

Answer 21

it’s very high. the attraction between cations and sea of electrons is very strong so lots of energy is required

Question 22

explain the solubility of metals

Answer 22

they are insoluble. the attraction between metal cations and electrons is much stronger than the attraction between water and metal cations

Question 23

how does the M.P of metals change across a period

Answer 23

its increases due to the atomic radius decreasing and the number of delocalised electron per atom increasing. the strength of attraction between electrons and metal cations increases so more energy is needed.

Question 24

how does the M.P of metals change down a group

Answer 24

it decreases due to the atomic radius and shielding increasing. this makes the attraction weaker so less energy is required.

Question 25

explain the conductivity of metals

Answer 25

they are great electrical conductors. the delocalised electrons are free to move through the lattice. the more outer electrons a metal has the better conductor it is

Question 26

define ductile

Answer 26

can be drawn into a wire

Question 27

define malleable

Answer 27

can be hammered into shape

Question 28

explain why metals are malleable

Answer 28

the layers of cations can easily slide over each other without disrupting the forces of attraction between the cations and electrons.

Question 29

what are crystals

Answer 29

solids in which the particles are in a regular lattice or arrangement held together by forces of attraction

Question 30

what are the types of crystal

Answer 30

ionic,
metallic,
giant covalent,
simple molecular

Question 31

explain the properties of simple molecules

Answer 31

low M.P- weak intermolecular forces
soft- weak intermolecular forces
brittle- movement disturbs the forces of attraction
insulators- no charged particles to carry a charge

Question 32

properties of diamond

Answer 32

very hard,
insulator,
insoluble,
very high M.P

Question 33

properties of graphite

Answer 33

soft,
conductor,
insoluble,
very high M.P

Question 34

properties of graphene

Answer 34

conductor,
very high M.P,
insoluble,
strong