Key concepts

Question 1

how are ions formed?

Answer 1

when atoms gain or lose electrons

Question 2

what is the plum pudding model?

Answer 2

that an atom was positively charged and contained negatively charged electrons

Question 3

how was the plum pudding model wrong?

Answer 3

because alpha particles passed straight through, deflected more than expected or even deflected backwards

Question 4

what is the nuclear atom?

Answer 4

an atom has a positive nucleus surrounded by negative electrons with empty space

Question 5

what is the bohr model?

Answer 5

shows that electrons can only exist in a fixed shell orbit with fixed energy

Question 6

what charge are protons?

Answer 6

positive

Question 7

what charge are neutrons?

Answer 7

neutral

Question 8

what charge are electrons?

Answer 8

negative

Question 9

what is the mass of a proton?

Answer 9

1

Question 10

what is the mass of a neutron?

Answer 10

1

Question 11

what is the mass of a electron?

Answer 11

negligible

Question 12

what charge does a nucleus have?

Answer 12

positive

Question 13

what does the nucleus contain?

Answer 13

protons and neutrons

Question 14

what charge to atoms have?

Answer 14

neutral - no charge

Question 15

why does an atom have no charge?

Answer 15

because they have the same number of protons as electrons

Question 16

why do ions have a charge?

Answer 16

because there isn’t the same number of protons and electrons

Question 17

what does the atomic number tell you?

Answer 17

how many protons an atom has

Question 18

what does the mass number tell you?

Answer 18

the total number of protons and neutrons

Question 19

which is bigger the mass or atomic number?

Answer 19

the mass number

Question 20

what are isotopes?

Answer 20

different forms of elements with the same number of protons and a different number of neutrons

Question 21

what is the relationship with the atomic and mass number of isotopes?

Answer 21

they have the same atomic number but different mass numbers

Question 22

what is relative atomic mass?

Answer 22

the average mass of one atom of the element compared to 1/12 of the mass of one atom of carbon12

Question 23

what happens if an element has one isotope?

Answer 23

it’s relative atomic mass with be the same as its mass number

Question 24

how to work out relative atomic mass from isotopic abundances

Answer 24

multiply each relative isotopic mass but it’s abundance and add up results
divide by the sum of abundances

Question 25

how did Mendeleev sort the elements originally?

Answer 25

through their properties

Question 26

what did he realise by doing this?

Answer 26

by putting the elements in order of atomic mass he could put the elements with similar chemical properties in columns

Question 27

How did Mendeleev fill in the gaps?

Answer 27

used properties of other elements in the columns to predict undiscovered elements properties

Question 28

what do groups show?

Answer 28

the number of electrons it has on its outer shell

Question 29

what do periods show?

Answer 29

how many full shells an element has

Question 30

how do negative ions form?

Answer 30

when atoms gain electrons

Question 31

do negative ions have more or less electrons than protons?

Answer 31

more

Question 32

how are positive ions formed?

Answer 32

when an atom loses electrons

Question 33

does a positive ion have more or less electrons than protons?

Answer 33

less

Question 34

what links electrons and charge?

Answer 34

the number of electrons lost or gained is the charge number

Question 35

what are ionic compounds made of?

Answer 35

a positively charged part and a negatively charged part

Question 36

what is the overall charge of an ionic compound?

Answer 36

zero

Question 37

what does it mean if an ion ends in ‘ate’?

Answer 37

they are negative ions containing oxygen and one other element

Question 38

what does it mean if an ion ends in ‘ide’?

Answer 38

negative ions containing only one element

Question 39

which ion is an acceptable to the rule when an ion ends in ‘ide’?

Answer 39

hydroxide ions as they are OH minus

Question 40

How is an ionic bond formed?

Answer 40

when a metal and non metal react together

Question 41

does a metal lose or gain electrons and what does it form?

Answer 41

loses electrons to form positive ion

Question 42

does a non metal gain or lose electrons and what does it form?

Answer 42

gains electrons to form a negative ion

Question 43

what is the structure of ionic compounds?

Answer 43

giant ionic lattice structures

Question 44

properties of ionic compounds

Answer 44

strong electrostatic forces high m and b points don’t conduct if a solid dissolve in water

Question 45

why does an ionic compound carry a current when a liquid or gas?

Answer 45

because the ions are free to move

Question 46

how are covalent bonds formed?

Answer 46

when two non metals share electrons between atoms

Question 47

What substance has covalent bonds?

Answer 47

simple molecular substances

Question 48

simple molecular substances properties

Answer 48

``` very strong covalent bonds weak intermolecular forces low m and b points don’t conduct some soluble some aren’t ```

Question 49

why do simple molecular substances not conduct?

Answer 49

because they don’t contain any free electrons

Question 50

what state of matter are molecular substances at room temp?

Answer 50

gas or liquid

Question 51

how do melting and boiling points increase?

Answer 51

if the molecule gets bigger, the strength of intermolecular forces increase so more energy is needed to break them

Question 52

what are polymers?

Answer 52

molecules made up of long chains of covalently bonded carbon atoms

Question 53

how do polymers form?

Answer 53

when lots of small monomers join together

Question 54

Giant covalent structure properties

Answer 54

strong covalent bonds high m and b points don’t conduct aren’t soluble

Question 55

why don’t giant covalent structures conduct?

Answer 55

because they don’t contain any charged particles

Question 56

Diamonds properties

Answer 56

``` has 4 covalent bonds high m and b point strong covalent bonds hard structure no delocalised electrons ```

Question 57

Graphite properties

Answer 57

forms three covalent bonds high melting and boiling point has one delocalised electron conducts electricity

Question 58

why is graphite a good lubricant?

Answer 58

because it’s layers can slide over each other as there are no covalent bonds between layers

Question 59

Fullerene properties

Answer 59

shaped like hollow balls or closed tubes carbon atoms in shape of hexagon huge surface area conduct electricity

Question 60

what are fullerenes used for?

Answer 60

drug delivery

Question 61

why is it good that fullerenes have a large surface area?

Answer 61

help make great industrial catalysts

Question 62

how are metallic bonds formed?

Answer 62

when two metals react together

Question 63

Metallic bond properties

Answer 63

``` electrostatic forces very strong high m and b points aren’t soluble can conduct delocalised electrons ```

Question 64

why are metals more dense?

Answer 64

the ions are packed closer together

Question 65

how are metals malleable?

Answer 65

layers can slide over each other

Question 66

properties of non metals

Answer 66

``` dull more brittle low density don’t conduct low m and b points gain electrons for full outer shell ```