Topic 6: Groups of the Periodic Table Flashcards
What are the names of the elements in group 1?
Alkali metals
What do group 1 elements have in common?
One electron in its outer shell
What are the properties of group 1 metals?
More reactive than other metals
Softer than other metals
Lower melting and boiling points than other metals
How do group one metals react?
Lose a single outer electron to from a stable 1+ ion
What is the trend with reactivity and group 1?
Reactivity increases as you go down the group
What do alkali metals make when they react with water?
Alkalis
This is a vigorous reaction
What are group 0 elements known as?
Noble gases
Do group 0 elements react? Why?
No - they have a full outer shell so are stable and inert
The colour of group 0 elements?
Colourless at room temperature
What is the trend with group 0 elements and density?
Increases as you go down the group
What is the trend with group 0 elements and melting and boiling points?
Increases as you go down the group
What are the properties of group 0 elements and their uses?
Inert - protect metals during welding
Non-flammable - used in filament lamps and flash photography
Low density (just helium) - fill balloons and airships
What are the elements in group 7 known as?
Halogens
What do the halogens exist as?
Diatomic molecules - they’re all two atoms joined by a COVALENT bond (2 non metals)
What colour is chlorine at room temperature?
Green
What is the test for chlorine?
Damp blue litmus paper
Put it in test tube
If it bleaches white, chlorine gas is present
What colour is bromine at room temperature?
Red brown liquid which gives off orange vapour
What colour is iodine at room temperature?
Dark grey solid which gives off purple vapour
What do halogens have in common?
They have 7 electrons in their outer shell
How do halogens react?
Gain an electron to form a 1- ion
What is the trend with group 7 elements and reactivity? Why?
Decreases as you go down the group - as outer shell is further from the nucleus so it’s harder to gain an electron
What is formed when a metal reacts with a halogen?
Metal halide
What is formed when hydrogen reacts with a halogen?
Hydrogen halide
What group has displacement reactions?
Halogens (group 7)
What type of reactions are displacement reactions?
Redox reaction
What group 7 element displaces all of the other group 7 elements? Why?
Fluorine
It’s at the top of the group - most reactive since reactivity decreases as you go down the group
What specifically happens in a displacement reaction?
The more reactive halogen displaces a less reactive halogen from its compound
What do hydrogen halides form when dissolved in water? Example?
Acidic solutions e.g. hydrochloric acid
Which halogen is reduced and which is oxidised in displacement reactions?
Reduced: the one that has gained electrons and displaced the other halogen
Oxidised: the one that has lost electrons and has been displaced
How can the trend of reactivity of halogens be predicted?
Carrying out displacement reactions - the more reactive displace the less and where the more reactive ones are, can be used to show how reactivity changes for the halogens
Describe the process of testing the reactivity of the halogens?
- React colourless aqueous chlorine with colourless aqueous potassium chloride and note down what you can see
- Repeat step 1 but instead of using colourless aqueous potassium chloride, use colourless aqueous potassium bromide then colourless aqueous potassium iodide STILL with colourless aqueous chlorine
- Repeat steps 1-2 with orange aqueous bromine and then brown aqueous iodine
