Knowledge

Created by

phoebe rackley

Cards (38)

Group 1  
-Alkali metals all have one outer electron, so they have similar chemical properties
Group 1 - Physical properties
-Low melting points and boiling points
-Very soft they can be cut with a knife
Group 1 - 
-Alkali metals form ionic compounds. They lose their single outer electron so easily that sharing it is out of the question, so they don't for covalent bonds
Group 1 is known as Alkali Metals
Group 1 - Reactivity
-Lose their single outer electron to form a 1+ ion with a stable electronic structure
-The more readily a metal loses its outer electrons, the more reactive it is
Group 1 - Reactivity
-As you go down Group 1, alkali metals get more reactive
-Outer electron is more easily lost because its further from nucleus (atomic radius is larger) so its less strongly attracted to the nucleus and less energy needed to remove it
Group 1 - Reactions with water
-When put in water they react vigorously
-Reaction produces hydrogen gas and a hydroxide of the metal.
Group 1- Reactions with water examples
-Lithium will move around surface, fizzing furiously
-Sodium and potassium do the same, but they also melt in heat of reaction.
-Potassium even gets hot enough to ignite the hydrogen gas being produced
Group 7 known as halogens
Group 7-  
-7 electrons in their outer shells so they all have similar chemical properties
-Halogens exist as diatomic molecules. Sharing one pair of electrons in a covalent bond gives both atoms a full outer shell
Group 7- Physical properties
-As you go down, the melting points and boiling points of halogens increase.
Group 7- Room temperatures
-Chlorine (Cl2) is a fairly reactive, poisonous, green gas
-Bromine (Br2) is a poisonous, red brown liquid, which gives off an orange vapour at room temp
-Iodine (I2) is a dark grey crystalline solid which gives off a purple vapour when heated
Group 7- Chlorine test  
-Hold a piece of damp blue litmus paper over chlorine gas
-Chlorine will bleach the litmus paper, turning it white.
Group 7- Reactivity  
-Halogen atom only needs to gain one electron to form a 1- ion with a stable electronic structure
-The easier it is for a halogen atom to attract an electron, the more reactive the halogen will be
Group 7 - Reactivity
As you go down group 7, halogens become less reactive, it gets harder to attract the extra electron to fill the outer shell when its further away from the nucleus (the atomic radius is larger)
Group 7- Reaction  
-Halogens react vigorously with some metals to form salts called 'metal halides'
-Halogens higher up in group 7 are more reactive because they can attract outer electron of metal more easily
Group 7- Reaction  
Halogens also react with hydrogen to form hydrogen halides. Hydrogen halides are soluble, and they can dissolve in water to form acidic solutions.
Displacement reaction -  
A displacement reaction is where a more reactive element 'pushes out' (displaces) a less reactive element from a compound
Halogen displacement reaction-  
The halogen displacement reactions are redox reactions. The halogens gain electrons (reduction) whilst halide ions lose electrons (oxidation)
Halogen displacement reaction-Example
-Chlorine is more reactive than bromine (its higher up Group 7). If you add water chlorine water (an aqueous solution of Cl2) to potassium bromide solution, the chlorine will displace the bromine from salt solution
-Chlorine is reduced to chlorine ions, so salt solution becomes potassium chloride. Bromide ions are oxidised to bromine which turns solution orange
Halogen displacement reaction- How to test
-Start by measuring out a small amount of a halide salt solution in test tube
-Add few drops of a halogen solution to it and shake tube
-If you see colour change, reaction has happened ~ halogen has displaced halide ions from salt. No reaction means no colour change
Potassium chloride solution + chlorine water
Colourless colourless
-No reaction
Potassium bromide solution + chlorine water
Colourless Colourless
-Orange solution formed (Br2)
Potassium iodide solution+ chlorine water
Colourless Colourless
-Brown solution (I2) formed
Potassium chloride solution + Bromine water
Colourless Orange
-No reaction
Potassium chloride solution + Iodine water
Colourless Brown
No reaction
Potassium bromide solution + Bromine water
Colourless Orange
No reaction
Potassium bromide solution + Iodine water
Colourless Brown
No reaction
Potassium iodide solution + Bromine water
Colourless Orange
Brown solution (I2) formed
Potassium iodide solution + Iodine water
Colourless Brown
No reaction
Group 0-  
Colourless gases at room temperature
Group 0-  
Noble gases are all monatomic (their gases are made up of single atoms)
Group 0-  
Inert, meaning they don't fully react with much. The reason for this is that they have a full outer shell of electrons. Meaning they don't easily gain electrons
Group 0-  
They are non-flammable as they are inert
Group 0- Everyday uses - Argon  
Argon is used in filament lamps. Since its non flammable, it stops very hot flammable from burning away
Flash photography uses same principle - argon, krypton and xenon are used to stop flash from burning up during high temperature flashes
Group 0- Everyday uses, Argon and Helium  
Argon and Helium can also be used to protect metals that are being welded. The inert atmosphere stops the hot metal reacting with oxygen
Group 0- Everyday uses, Helium  
Helium is used in airships and party balloons. Helium has a lower density than air- so it makes balloons float. It also non flammable which makes it safer to use than hydrogen gas
Group 0- Properties of noble gases
-Melting point and boiling point and density all increase as you go down Group 0