Groups in the Periodic table

Question 1

how many outer shell electrons do alkali metals have?

Answer 1

1 - so they all have similar chemical properties

Question 2

what are the properties of alkali metals?

Answer 2

very soft - they can be cut with a knife

relatively low melting points

Question 3

What kind of compounds do they form?

Answer 3

ionic compounds - they lose their single electron so easily

Question 4

what do the alkali metals become (ions)?

Answer 4

1+ ion with a stable electronic structure

Question 5

How do you tell how reactive an element is?

Answer 5

the more readily an electron is to lose its outer electron, the more reactive it is

Question 6

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

Answer 6

they get more reactive -the outer election is more easily lost as it is further away from the nucleus so it is less strongly attracted meaning less energy is need to remove it

Question 7

What is the equation when alkalis react with water?

Answer 7

sodium + water –sodium hydroxide + hydrogen

Question 8

Lithium and water reaction

Answer 8

move around the surface and fizz furiously

Question 9

sodium and potassium

Answer 9

will melt in the reaction, potassium gets hot enough to ignite the hydrogen gas being produced

Question 10

How are the halogens bonded?

Answer 10

covalent bonding

Question 11

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

Answer 11

they increase

Question 12

what substance is chlorine at room temp?

Answer 12

fairly reactive, poisonous, green gas

Question 13

what substance is bromine at room temperature?

Answer 13

poisonous, red/brown liquid which gives off an orange vapour

Question 14

what substance is iodine at room temp?

Answer 14

a dark grey crystalline solid which gives off a purple vapour when heated

Question 15

what is the test for chlorine?

Answer 15

hold a piece of damp blue litmus paper over it, the chlorine will turn the litmus paper red and then bleach it white

Question 16

what kind of ions do halogens create?

Answer 16

they gain an electron to become 1-

Question 17

What does the reactivity do as you do down the group of halogens?

Answer 17

as you go down group 7, the halogens become less reactive - it gets harder to attract the extra electron to fill the outer shell when its further away from the nucleus

Question 18

What do the Halogens react vigourously with?

Answer 18

metal halides

Question 19

why are halogens at the top of the group more reactive?

Answer 19

the can attract the electron more easily

Question 20

halogen reacting with hydrogen

Answer 20

chlorine + hydrogen – hydrogen chloride

Question 21

what are hydrogen halides?

Answer 21

hydrogen and halides mixed together, they are soluble to form acidic solutions

Question 22

what happens when a halogen reacts with another halogen salt solution?

Answer 22

its the halogen is more reactive than the solution, it displaces the solution

Question 23

what happens when chlorine reacts with potassium bromide?

Answer 23

the chlorine will displace the bromine

the chlorine is reduced to chloride ions and the bromide ions is oxidised to form bromine

Question 24

what substance is the noble gas at room temp?

Answer 24

colourless gas

Question 25

what are the properties of the noble gases?

Answer 25

inert- they don’t react much as they have a full outer shell this means they don’t easily gain or lose electrons

Question 26

what is argon used for and why?

Answer 26

filament bulbs - its non flammable so it stops everything in the bulb from burning away

Question 27

what is helium used for and why?

Answer 27

used in airships and balloons - it has a low density than air so it makes balloons float and it is non flammable so it is safer to use than hydrogen gas

Question 28

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

Answer 28

they all increase