Chemical bonding

Question 1

What are isotopes

Answer 1

atoms of the same element with different numbers of neutrons and therefore a different mass numbers

Question 2

What do ionic bonds consist of

Answer 2

Non metal and metal

Question 3

What do metals want to lose in reactions

Answer 3

electrons

Question 4

What do non metals want to gain in reactions

Answer 4

electrons

Question 5

What ions do metals form

Answer 5

cations

Question 6

what ions do non metals from

Answer 6

anions

Question 7

what are positive and negative ions held together by

Answer 7

electrostatic forces of attraction

Question 8

why do ionic substances have high mpt and bpt

Answer 8

strong electrostatic forces of attraction between oppositely charged ions throughout the giant structure

Question 9

why are ionic substances hard but brittle

Answer 9

strong forces if attraction
when layers slide, ions of the same charge align and the structure breaks

Question 10

why are ionic substances soluble in water

Answer 10

ions are attracted to the polar water molecules and this attraction breaks the lattice apart

Question 11

why don’t ionic substances conduct in a solid form

Answer 11

the ions are held in position and are not free to move

Question 12

why do ionic substances conduct in molten form

Answer 12

the ions are free to move

Question 13

what are covalent bonds formed between

Answer 13

non metals

Question 14

what does a covalent bond consist of

Answer 14

shared pairs of electrons

Question 15

what is a simple covalent structure

Answer 15

composed of molecules - particles made up of atoms bonded strongly together by covalent bonds

Question 16

what is a giant covalent structure

Answer 16

contain millions of atoms bonded by many strong covalent bonds to form a giant molecule

Question 17

why are mpt and bpt of simple molecular low

Answer 17

only weak intermolecular forces between molecules that need little energy to overcome

Question 18

why is electrical conductivity of simple molecular poor

Answer 18

no ions or free electrons present

Question 19

why is solubility in water of simple molecular poor

Answer 19

no charged particles to be attracted to water molecules

Question 20

what are diamond and graphite forms of

Answer 20

carbon

Question 21

why do diamond and graphite have different physical properties

Answer 21

in diamond each carbon atom is joined to 4 others by strong covalent bonds, meaning it is very hard. In graphite there are strong covalent bonds within a layer of carbon atoms but weak intermolecular forces between layers, therefore softer

Question 22

melting points of diamond

Answer 22

high due to strong covalent bonds that have to be broken

Question 23

melting point of graphite

Answer 23

high as lots of covalent bonds have to be broken

Question 24

electrical conductivity of diamond

Answer 24

no delocalised electrons as all outer electrons are in covalent bonds

Question 25

electrical conductivity of graphite

Answer 25

good due ro delocalised electrons between layers that can slide easily

Question 26

industrial uses of diamond

Answer 26

drill bits due to hardness jewellery due to shininess

Question 27

industrial uses of graphite

Answer 27

pencils, lubrication due to layers that slide over each other used as electrodes due to good conductivity

Question 28

how are atoms in metals held together

Answer 28

metallic bonds

Question 29

what are metallic bonds

Answer 29

metal ions , consisting of the nucleus and inner shells, are held together by the outer shell electrons, which come delocalised with a freedom to move

Question 30

wy are melting points and boiling points high in metals

Answer 30

lots of energy needed to break the attractive forces between the delocalised electrons and the positive ionsh

Question 31

why are metals malleable and ductile

Answer 31

layers of ions can slide over each pother when a force is applies

Question 32

why are metals good conductors of electricity

Answer 32

electrons in the sea of delocalised electrons are free to move and can flow when a potential difference is applied

Question 33

why are metals good conductors of heat

Answer 33

delocalised electrons gain kinetic energy when heated and move faster throughout the material transferring heat

Question 34

what are alloys

Answer 34

mixtures of metals bonded together metallically in a giant lattice

Question 35

why aren't alloys compounds

Answer 35

atoms of different substances are not bonded chemically to one another. thy have not reacted of changed, and react how the separate elements react

Question 36

why are alloys stronger than pure metals

Answer 36

the foreign metals prevent the layers of metal atoms from sliding over each other

Question 37

what is graphene

Answer 37

a single layer of graphite strongest known substance

Question 38

what is fullerene

Answer 38

allotropes of carbon have low mpt and bpt as they have weak intermolecular forces between molecules