sc17, groups in the periodic table (paper 2)

Question 1

what group are the alkali metals in

Answer 1

1

Question 2

what is the name given to elements in group 1

Answer 2

alkali metals

Question 3

properties of alkali metals

Answer 3

• good conductors of heat + electricity
• shiny when freshly cut
• softer
• relatively low melting points (still solid)

Question 4

what are the products from reactinf alkali metals with water

Answer 4

metal hydroxide + hydrogen

Question 5

true or false: the alkali metals reactivity decrease as you go down the group

Answer 5

false

Question 6

true or false: the alkali metals reactivity increase as you go down the group

Answer 6

true

Question 7

why does the reactivity of alkali metals increase as you go down the group? [3 marks]

Answer 7

as you go down:
- the number of occupied shells in an atom increases
- the electrons in the inner shell shield the outer electron
- so, the attraction to the nucleus is weaker and more likely to be lost

Question 8

true or false: lithium, sodium and potassium are more dense than water so they don’t float

Answer 8

false

Question 9

true or false: lithium, sodium and potassium are less dense than water so they float

Answer 9

true

Question 10

true or false: lithium, sodium and potassium are stored in oil to keep air and water away

Answer 10

true

Question 11

true or false: lithium, sodium and potassium aren’t stored in oil to not keep air and water away

Answer 11

false

Question 12

how does lithium react with water

Answer 12

fizzes steadily

Question 13

how does sodium react with water

Answer 13

• melts into a ball from the released heat
• fizzes rapidly

Question 14

how does potassium react with water

Answer 14

• gives off sparks
• produces hydrogen that burns with a lilac coloured flame

Question 15

what group are the halogens in

Answer 15

7

Question 16

what is the name given to elements in group 7

Answer 16

halogens

Question 17

true or false: the halogens reactivity decrease as you go down the group

Answer 17

true

Question 18

true or false: the halogens reactivity increase as you go down the group

Answer 18

false

Question 19

define a halide

Answer 19

compounds of metals or hydrogen with halogens, such as sodium chloride

Question 20

what is produced when a hydrogen reacts with a halogen

Answer 20

hydrogen halide

Question 21

why does the reactivity of halogens decrease as you go down the group? [3 marks]

Answer 21

as you go down:
- the outer shells get further away from the nucleus
- more shielding by inner electrons
- the attraction between the electron and nucleus get weaker
- electrons are gained less easily

Question 22

how is a hydrogen halide formed

Answer 22

• when hydrogen reacts with a halogen
• which produces a hydrogen halide
• that dissolves in water to produce acidic solutions

Question 23

what colour is fluorine

Answer 23

yellow

Question 24

what colour is chlorine

Answer 24

green

Question 25

what colour is bromine

Answer 25

brown

Question 26

what colour is iodine

Answer 26

grey-black

Question 27

what group are the noble gases in

Answer 27

0

Question 28

what is the name given to elements in group 1

Answer 28

noble gases

Question 29

why are noble gases inert

Answer 29

• their atoms have full outer shells of electrons
• they have no tendency to lose, gain or share electrons

Question 30

why is helium used as a lifting gas

Answer 30

• it has a low density and is inert
• less dense than air, so it rises
• non flammable so it doesn’t ignite

Question 31

why is argon, kyrpton axenon used as a filling gas

Answer 31

• it’s inert
• the metal filament glows as it’s hot
• the inert gas stops it from burning away

Question 32

why is argon used as a shielf gas

Answer 32

• it’s inter
• it is denser than air so it keeps it away from metal
• it also doesn’t oxidise