C3 - Alkali Metals & Halogens Flashcards
What are the 2 things that change as you go down group 1?
They become more reactive
They have lower melting and boiling points
What are alkali metals?
Group 1 metals (one outer electron)
What are the 2 other basic properties of the alkali metals and why?
Very reactive (1 outer electron)
Low density
Why do alkali metals get more reactive as you go down?
The outer electron is further from the nucleus so it is more easily lost
How are alkali metals stored and transferred?
Stored in oil and handled with tongs etc.
Describe what is produced when alkali metals react with non-metals by ionic bonding
White compounds that dissolve in water to form colourless solutions
Describe what happens in terms of chemistry when an alkali metal is put into water
The alkali metals and water react to form a metal hydroxide and hydrogen gas (H^2)
The metal hydroxide dissolves in water to give alkaline solution
For example, 2Na + 2H^2O –> 2NaOH(aq) + H^2
Describe what can be seen when an alkali metal reacts with water
The alkali metal floats around the surface, fizzing
The hydrogen gas that is given off is ignited by the heat of the metal to produce tiny explosions (pops)
What are halogens?
Group 7 (7 outer electrons)
What are the 2 things that change as you go down group 7?
Less reactive
Higher melting and boiling points
Why do the halogens get less reactive as you go down?
Harder to gain other electron because outer shell is further from nucleus
Describe the features of fluorine, chlorine, bromine and iodine
Fluorine is a very reactive, poisonous yellow gas
Chlorine is a fairly reactive, poisonous dense green gas
Bromine is a dense, poisonous, red-brown volatile liquid
Iodine is a dark grey crystalline solid or a purple vapour
What is common about the way that the halogens naturally are?
They are all diatomic (exist as pairs of atoms)
What is a halide?
A halogen ion (1- charge)
What can the more halogens do?
Displace less reactive ones
Describe how more reactive halogens displace less reactive ones
The more reactive halogen is fed as a gas into a solution of a salt of the less reactive halogen
2 solutions are formed: the less reactive halogen (diatomic still) and the same salt solution but with the more reactive halogen
What are the 4 main chemical properties of transition metals?
Good conductors of heat and electricity
Dense, strong and shiny
Much less reactive than alkali metals
Generally higher melting points than alkali metals
What are the 3 other properties of transition metals?
Usually have more than one ion (like Fe^2+ and Fe^3+)
Compounds of them are very colourful due to the transition metal ion
Transition metals and their compounds are very good catalysts
