C4 Flashcards
What are the Group 1 elements known as?
Alkali Metals
Why do alkali metals have similar properties?
They all have 1 outer electron
What are the physical properties of alkali metals?
Very soft - can be cut with a knife
How can you test for alkali metals?
Flame tests
Why are alkali metals very reactive?
They readily lose their single outer electron to form a positive ion - the more readily a metal becomes an ion, the more reactive it is.
Why do alkali metals get increasingly reactive as you move down the group?
The outer electron is easier to lose when the outer shell is further away from the nucleus (the atomic radius is larger).
How do alkali metals in general behave in water?
They react vigorously. The reaction produces hydrogen gas and a hydroxide of the metal.
How does Lithium behave in water?
It moves around the surface, fizzing furiously
How do Sodium and Potassium behave in water?
Similarly to Lithium, but they also melt in the heat of the reaction
How do Rubidium and Caesium behave in water?
They react violently with water, tending to explode when they get wet.
What is produced when alkali metals react with dilute acids?
A salt and hydrogen gas. This reaction is very violent.
What are Group 7 elements known as?
Halogens
Why do halogens have similar properties?
They all have 7 electrons in their outer shell.
Halogens exist as diatomic molecules - what does this mean?
They are made up of two atoms of the element eg. Cl₂
How do halogens gain a stable electronic structure?
They share one pair of electrons in a covalent bond, giving both atoms involved a full outer shell.
What happens to the melting and boiling point of halogens as you move down the group?
The melting points of the halogens increase.
How does chlorine behave at room temperature?
It is fairly reactive, poisonous, green gas.
How does bromine behave at room temperature?
It is a poisonous, red-brown liquid, which gives off an orange vapour at room temperature.
How does iodine behave at room temperature?
It is a dark grey crystalline solid, which gives off purple vapour when heated.
Why do halogens become less reactive as you move down the group?
It is harder for them to attract an extra neutron to fill their outer shell when it’s further away from the nucleus (the atomic radius is larger).
What happens when halogens react with alkali metals?
They react vigorously and form salts known as metal halides.
What is a displacement reaction?
It is where a more reactive element “pushes out” (displaces) a less reactive element from a compound
What does it mean if there is a colour change when you mix a halide salt and a halogen solution?
It means that the halogen has displaced the halide ions from the salt.
What happens when you react Chlorine with Potassium Chloride, Potassium Bromide and Potassium Iodide?
Potassium Chloride: No reaction
Potassium Bromide: Orange solution formed (Bromide displaced)
Potassium Iodide: Brown solution formed (Iodide
What happens when you react Bromine with Potassium Chloride, Potassium Bromide and Potassium Iodide?
Potassium Chloride: No reaction
Potassium Bromide: No reaction
Potassium Iodide: Brown solution formed (Iodide displaced)
What happens when you react Iodine with Potassium Chloride, Potassium Bromide and Potassium Iodide?
Potassium Chloride: No reaction
Potassium Bromide: No reaction
Potassium Iodide: No reaction
What are Group 0 elements known as?
Noble gases.
How do noble gases behave at room temperature?
They are all colourless gases.
Noble gases are monatomic - what does monatomic mean?
It means that they are made up of single atoms.
What does inert mean?
It means that something doesn’t react.