Chemistry : Groups in the Periodic Table Flashcards
What are the Group 1 Metals known as?
The ‘Alkali Metals’
What are the metals in Group 1?
Lithium, sodium, potassium, rubidium, caesium, francium
How many electrons do the metals in Group 1 have in their outer shell?
1, so they have similar chemical properties
What physical properties do they all share?
Low melting and boiling points
Very soft, they can be cut with a knife
What kind of compounds do the form?
Ionic, as they lose their outer electron so easily they cannot share it, so can’t form covalent bonds
Are Group 1 metals reactive?
Yes, they are very reactive
Why do the alkali metals get more reactive the further down you go?
The outer most electron gets further from the nucleus so is less strongly attached to it and needs less energy to remove it
What happens when an alkali metal reacts with water?
They react vigorously
What does a reaction between an alkali metal and water produce?
Hydrogen gas and a hydroxide of the metal
How does lithium react with water?
It will move around on the surface, fizzing furiously
How do sodium and potassium react with water?
They will move around on the surface, fizzing furiously, but they will also melt due to the heat of the reaction
Potassium even gets hot enough to ignite the hydrogen gas produced
What are the Group 7 elements known as?
The ‘Halogens’
What elements make up Group 7?
Fluorine, chlorine, bromine, iodine and astatine
How many elements are in the outer shell of the halogens?
7, so they have similar chemical properties
How do the halogens exist as?
Diatomic molecules (e.g. Cl2, Br2), sharing one pair of electrons in a covalent bond gives both atoms a full outer shell
Does the melting and boiling points increase or decrease as you go down Group 7?
They increase
At room temperature, what is chlorine like?
It is a fairly reactive, poisonous, green gas
At room temperature, what is bromine like?
It is a poisonous, red-brown liquid, which gives off an orange vapour at room temperature
At room temperature, what is iodine like?
It is a dark grey crystalline solid which gives off a purple vapour when heated
How can you test for chlorine?
Using a damp blue piece of litmus paper, it will bleach if it comes into contact with chlorine
It may turn red for a moment, as chlorine is acidic
Is it easier for a halogen atom to gain or loss an electron?
Gain, as this would form a full outer shell
Why do the halogens become less reactive as you go down the group?
It gets harder to attract the extra electron to fill the outer shell when it’s further away from the nucleus
What happen when the halogens react with some metals?
They will react vigorously, forming salts called ‘metal halides’
What can halogens react with to form hydrogen halides?
Hydrogen
What are the properties of hydrogen halides?
Soluble and can dissolve in water to form acidic solutions, e.g. HCl forms hydrochloric acid in water
Will a more reactive halogen displace a less reactive one?
Yes, the elements in group 7 take part in displacement reactions
What is a displacement reaction?
It is where a more reactive element displaces a less reactive element from a compound
What are the halogen displacement reactions also?
Redox reactions, the halogens gain electrons (reduction) and the halide ions lose electrons (oxidation)
What is the colour of potassium bromide with chlorine water?
Orange solution (Br2) is formed
What is the colour of potassium iodide with chlorine water?
Brown solution (I2) is formed
What is the colour of potassium iodide with bromine water?
Brown solution (I2) is formed
Does chlorine displace bromine and/or iodine?
No, it doesn’t displace either
Does bromine displace chlorine and/or iodine?
Bromine displaces chlorine but not iodine
Does iodine displace chlorine and/or bromine?
Yes, it displaces both
What are the elements in group 0 known as?
The ‘Noble Gases’
What elements make up group 0?
Helium, neon, argon, krypton, xenon, radon
What are all the elements in group 0 at room temperature?
Colourless gases
Are all the noble gases monatomic or diatomic?
Monatomic, meaning they all are made up of single atoms, not molecules
Are noble gases really reactive?
No, they are more or less inert
This is because they all have full outer shells so don’t give up or gain any electrons electrons
Are noble gases flammable?
No, they are non-flammable
Why did it take so long for the noble gases to be discovered?
The properties of these gases were hard to observe, so they were hard to find
What are some of the examples of noble gas usage in everyday life?
Can be used to provide an inert atmosphere
Argon does this in filament lamps, it stops the very hot filament from burning away
Argon, krypton and xenon are all used in flash photography to stop the flash filament from burning up
Argon/helium are used to protect metals that are being welded
Helium is used in airships and balloons
Do the melting/boiling points and density increase or decreases as you go down group 0?
They all increase
