What is a group?
Elements in the column
What is a period?
Elements in a row
Where are metals in the periodic table?
On the left and middle
Where are non metals in the periodic table?
On the right
Are metals electrically conductive?
Are non metals electrically conductive?
Are metal oxides acid or alkali?
Are non metal oxides acid or alkali?
Why do elements in the same group of the periodic table have the same chemical properties?
Because they all have the same number of electrons in their outer shell and therefore give away or gain the same amount of electrons when they react with another element
What are the noble gases?
A group of inert gases
Why are noble gases extremely unreactive?
Because they all have a full outer shell of electrons and therefore have no need to gain or lose any electrons by reacting with another element
Describe the reaction of lithium with water
Lithium doesn't melt but fizzes on the surface of the water and produces an alkaline solution
Describe the reaction of sodium in water
Sodium melts into a small ball on the surface of the water giving of hydrogen, producing an alkaline solution. Sodium catches fire with an orange flame on filter paper on top of the water.
Describe the reaction of potassium with water
Potassium melts giving off hydrogen which catches fire with a LILAC flame producing an alkaline solution.
How does the melting/boiling point of the group 1 metals change as you go down?
It decreases, i.e. Lithium is highest
How does the density of group 1 metals change as you go down the group?
It increases, i.e. lithium is least dense
Think about how lithium sodium and potassium are all less dense than water and float on it
How should you store group 1 metals and why?
Lithium, sodium and potassium should all be stored on oil because they all react quickly with air to form oxides and violently with water.
Rubidium and caesium are so reactivw that they have to be stored in a sealed glass container to stop any possibility of oxygen getting to them.
What colour are group 1 metal ions?
And so what colour are their compounds?
colourless or white unless they are paired with a coloured negative ion
How does the reactivity change as you go further down the group 1?
The elements become more reactive as you go further down the group
In conclusion group 1 elements:
• are metals
• are soft with melting points and densities that are very low for metals
• have to be stored out of contact with air and water
• react rapidly with air to form coatings of the metal oxide
• react with water to produce an alkaline solution of the metal hydroxide and hydrogen gas
• increase in reactivity as you go down the group
• form compounds in which the metal has a 1+ ion
• have mainly white compounds which dissolve to produce colourless solutions
What are the alkali metals?
Group 1 metals
Why do elements in group 1 get more reactive as you move further down the group?
Because the outer electron is further from the nucleus which means the attraction between the nucleus and electrons is less and so the electron is more easily lost.
What is the colour and state of chlorine at room temperature?
What is the colour and state of bromine at room temperature?
What is the colour and state of iodine at room temperature?
Predict the properties of other halogens in this group
Black/grey solid 7 outer shell electrons Less reactive than other halogens
How does the reactivity change in group 7?
Elements become less reactive as you go further down the group
Why do elements in group 7 become less reactive as you go further down the group?
Because it's harder to gain an extra electron because the outer shell is further from the nucleus and so there is less attraction.
How are the halogens dangerous?
Fluorine is extremely reactive.
They all have very poisonous vapours and so should be handled in a fume cupboard.
Liquid bromine is corrosive
Describe an experiment to show that a more reactive halogen will displace a less reactive halogen and form a solution of one of its salts.
Sodium bromide + chlorine = sodium chloride + bromine
Sodium iodide + chlorine = sodium chloride + iodine