chemistryyy

Question 1

Whose ideas did John Newlands build on on the periodic table ( in in 1864)

Answer 1

John Dalton’s

Question 2

What idea of his did John Newlands use his periodic table to demonstrate

Answer 2

‘Law of Octaves’

Question 3

What two things did Mendeleev do to his table that Newlands did not?

Answer 3

He left gaps in the table and predicted what the gaps would be
He also swapped the order of some of the elements

Question 4

What two elements did Mendeleev swap round and why

Answer 4

Telerium and iodine because their atomic properties didn’t match their mass - although telerium has a higher atomic mass, iodine has a higher atomic number so he put that in front of tellurium on the periodic table

Question 5

What similarities did Mendeleev and Newlands have with their periodic tables??

Answer 5

They both arranged it by mass

Question 6

Why was Newland’s ideas not recognised why his peers (2 reasons)

Answer 6

Some boxes had two elements ( for no reason in particular)
He arranged it according to a piano (why?!)

Question 7

3 important details between mendeleev’s table and the modern periodic table

Answer 7

1 - modern one is arranged by atomic number not atomic mass (mass number)
2 -modern one has no gaps, elements have been discovered
3 - in mendeleev’s table a whole group - noble gases - group 0/8 was omitted because they hadn’t been discovered yet

Question 8

how many elements were there in mendeleev’s table compared to the modern one (roughly)

Answer 8

63, there are now 118

Question 9

what is a group on the periodic table

Answer 9

a vertical column

Question 10

what is a period on the periodic table

Answer 10

a horizontal row

Question 11

what do elements in the same group have in common?

Answer 11

they have the same number of electrons in their outer shell and therefore have similar chemical properties

Question 12

what do elements in the same period have in common?

Answer 12

they have the same number of electron shells, so therefore have similar chemical properties

Question 13

where are the transition metals between

Answer 13

the elements in the gap between groups 2 and 3

Question 14

what is the difference between metal and non- metal oxides

Answer 14

metal oxides are basic compounds, however non-metal oxides are acidic compounds

Question 15

what is another name for the group 2 elements in the periodic table

Answer 15

Alkaline earth metals

Question 16

what is another name for the group 1elements in the periodic table

Answer 16

Alkali metals

Question 17

what is another name for the group 7 elements in the periodic table

Answer 17

halogens

Question 18

what is another name for the group 0/8 elements in the periodic table

Answer 18

noble gases

Question 19

make two comparisons of titanium and sulphur’s properties

Answer 19

1. titanium is a shiny silvery metal, whereas sulphur is yellow solid (and non metal)
2. titanium conducts electricity while sulphur does not

Question 20

How does hardness change as you go down the group with alkali metals and why is this?

Answer 20

As you go down the group, the metals become softer and easier to cut - due to the metallic bond getting weaker

Question 21

How does density change as you go down the group with alkali metals and why is this?

Answer 21

The elements get denser, because of the atoms of the elements increasing in size

Question 22

which alkali metals are less dense than water

Answer 22

lithium, sodium and potassium

Question 23

which alkali metals are denser than water

Answer 23

rubidium and caesium

Question 24

do alkali metals have high or low boiling points?

Answer 24

low

Question 25

how and why does the melting point change as you go down the alkali metals

Answer 25

it decreases, as the metallic bonding gets bigger due to the bigger atoms

Question 26

why do alkali metals have to be stored in oil?

Answer 26

because they are very reactive and otherwise would react with the oxygen and water vapour in the air

Question 27

metals go from shiny to ? when cut ( ad in the presence of oxygen)

Answer 27

dull, tarnished

Question 28

5 things happen when alkali metals react with water: 1 - they ? 2 - Li, Na and K float on the ? 3 - Na and K ? 4 - ? Rb and Cs -> flame (fire) 5 - leaves behind a very ? solution at the end - pH 14, cause by ? ion

Answer 28

fizz, surface, melt, K, alkaline, OH-

Question 29

give a word equation for what happens when lithium reacts with water

Answer 29

lithium + water -> lithium hydroxide + hydrogen

Question 30

what gas is given off after a reaction between an alkali metal and water

Answer 30

hydrogen

Question 31

give a balanced symbol equation for a reaction between lithium and water :

Answer 31

2Li + 2H2O-> 2LiOH +H2

Question 32

what happens to the reactivity of alkali metals as you go down the group and why?

Answer 32

they get more and more reactive, as the electron in the outer shell gets further away from the nucleus so is less attracted to it and therefore gets easier to lose

Question 33

3 common features of alkali metal compounds ( eg NaCl )

Answer 33

they are white solids, they are always soluble in water, when dissolved in water they are always colourless

Question 34

what type of molecules do elements in group 7 form

Answer 34

diatomic molecules

Question 35

as you go down the halogens, what happens to the melting and boiling points??

Answer 35

they increase

Question 36

what colour is fluorine as a pure element

Answer 36

pale yellow

Question 37

what colour is chlorine as an element and as dissolved in water

Answer 37

green as pure element, and pale green in water

Question 38

what colour is bromine as a pure element and dissolved in water

Answer 38

red/brown as a pure element and orange in water

Question 39

what colour is iodine as a pure element and as dissolved in water

Answer 39

grey, shiny (solid) and brown in water

Question 40

what colour is astatine as a pure element

Answer 40

black

Question 41

what happens to the covalent bonds as you go down the halogens

Answer 41

they get weaker

Question 42

why does the melting points of halogens get higher as you go down the group?

Answer 42

because as you go down the group the intermolecular forces between the (diatomic) molecules get stronger and so require more energy to break them therefore higher melting (and boiling) points

Question 43

what type of compound is formed when a halogen reacts with a metal and what type of bonding is this

Answer 43

a halide, ionic bonding

Question 44

a halide reaction is called direct ? as two ? simply combine to form a ?

Answer 44

combination, elements, compound

Question 45

give a word equation for the direct combination reaction between aluminium and chlorine :

Answer 45

aluminium + chlorine -> aluminium chloride

Question 46

what is it called when an element gains electrons

Answer 46

reduction

Question 47

what is it called when an elements loses electrons

Answer 47

oxidation

Question 48

Al has gone to Al3+, is this reduction or oxidation - and write a half equation to show this

Answer 48

oxidation, as Al has lost 3 electrons - Al -> Al3+ + 3e-

Question 49

what happens to the reactivity of the halogens as you go down the group

Answer 49

they get less and less reactive

Question 50

is the trend for reactivity in group 1 and group 7 the same or different, why?

Answer 50

different as in group 7 it works the opposite as halogens need to gain an electron so halogens at the top of the group have smaller atoms - so therefore a greater attraction to the nucleus making it easier for them to gain an electron and making them more reactive

Question 51

What two things do displacement reactions need to take place

Answer 51

A halogen element - eg chlorine (Cl2) A compound of another halogen - eg sodium bromine (NaBr)

Question 52

in displacement reactions a ? reactive halogen element will displace a ? reactive halogen from the compound

Answer 52

more, less

Question 53

what causes colour change in a displacement reaction?

Answer 53

the leftover halogen element product

Question 54

in a displacement reaction eg : chlorine + sodium bromide -> sodium chloride + bromine which part would cause colour change

Answer 54

bromine - would cause a yellow orange colour to form

Question 55

Group 0/8 - the ? gases are all ? gases with a full ? shell of electrons

Answer 55

noble, unreactive, outer

Question 56

What type of molecules/atoms do noble gases exist as

Answer 56

monatomic - single atoms

Question 57

noble gases are all colourless at ? temperature and as their atomic number increases their densities and ? points also increase

Answer 57

room, boiling

Question 58

how does the force of attraction between noble gas atoms change

Answer 58

they increase with atom size, therefore melting point increases

Question 59

what are the forces between noble gas atoms called

Answer 59

van der waal forces

Question 60

noble gases : as the ? mass increases, the boiling point also ? due to ? forces between atoms

Answer 60

atomic, increases, large/strong

Question 61

what is helium used in and why

Answer 61

1 - balloons - low density - floats 2 - diving - can dive lower - helium insoluble in blood

Question 62

Why is helium being insoluble in blood such a good thing

Answer 62

using nitrogen instead causes small bubbles in the blood can lead to bends ( a dangerous medical condition) helium does not do this !

Question 63

what is neon used for

Answer 63

neon lights

Question 64

what is argon used in??

Answer 64

lightbulbs - prevents filament from burning

Question 65

what are both krypton and xenon used in..?

Answer 65

lasers

Question 66

what is radon and how does it cause problems when you are in its presence

Answer 66

a radioactive gas, can cause cancer is a health hazard in general

Question 67

transition metals have ? properties because as you go across the rows an ? electron shell ( the ? shell) is being filled

Answer 67

similar, inner, 3rd

Question 68

the 3rd shell can hold a max of ? electrons once the 4th shell holds at least ? electrons

Answer 68

18, 2

Question 69

transition metals have many typical physical properties of metals, what are they? (give 4 answers)

Answer 69

good conductor of electricity ductile and malleable shiny sonorous (sounds nice)

Question 70

transition metals are ? reactive than main block ? (eg: sodium and magnesium) transition metals are also good ? meaning they can speed up a reaction without being used up

Answer 70

less, metals, catalysts

Question 71

t metals also form compounds which are ?, eg copper sulphate is ? , these compounds are used as a ? when making pottery. also when in the presence of carbon dioxide and moisture ( from ?) , copper reacts to produce a ? film which is called verdigris and is found on statues eg statue of ?

Answer 71

coloured, blue, dye, air, green, Liberty

Question 72

t metals can also produce more than one ?, eg: ?can only form one ion - Mg2+, while copper can form two - Cu+ and ? and iron forms ? as well - ? and Fe3+

Answer 72

ion, magnesium, Cu2+, two, Fe2+

Question 73

why are iron and steel used in construction

Answer 73

are transition metals - very strong, malleable ductile able to be drawn into a line and made into things and are far less reactive than other metals so won't decay or react with the air as much

Question 74

why are some saucepans made out of copper

Answer 74

copper is a good conductor of electricity and so it heats up the water more quickly

Question 75

how to test for chlorine

Answer 75

damp blue litmus paper will turn white

Question 76

what gas dissolves in water to form hydrochloric acid

Answer 76

hydrogen chloride

Question 77

what is a redox reaction

Answer 77

a reaction with reduction and oxidation in it - a reaction where electrons are lost and gained!!