What are group 1 metals also known as?
Alkali Metals
What are group 7 also known as
Halogens
What are group 0 also known as?
Noble gases
Names some physical properties of Alkali metals
Very soft so can be cut with a knife
Low melting points
What kind of compounds do group 1 form? and Why?
Ionic compounds because they lose their outer shell electron very easily
What is the pattern f reactivity going down the group 1
Increases/ more reactive
What happens when lithium sodium and potassium react with water
Produces a metal hydroxide and hydrogen gas
fizzes and bubbles in the water
How do we test for hydrogen
squeaky pop test
Why do group 1s get more reactive
because their outer shell electron is lost more easily as its further from the nucleus
Why does potassium ignite when reacting with water??
Because it gets hot enough to ignite the hydrogen gas being produced
What is the balanced symbol equation for Alkali metal reacting with water (for sodium)
2Na + 2H2O»_space;» 2NaOH + H2
-Works for all group 1
What is the half equation for lithium forming a 1+ ion in an ionic compound
Li»_space;»> Li+ + e-
What is the appearance and state of chlorine, bromine, and iodine at room temperature
Chlorine - fairly reactive, poisonous green gas
Bromine- poisonous brown liquid which gives off orange vapour
Iodine- dark grey crystal solid which gives off purple vapour when heated
What are the trends in colour as you go down the group 7
The colours get darker
How does reactivity change as you go down group 7
decreases as its harder to attract an extra electron as its outer shell is too far from the nucleus
How do boiling and melting points change as you go down group 7
It increases as they become solids as you go down so more energy is needed to break bonds
Predict the properties of Astatine (bottom of group 7)
Black solid with very high melting point of 300 degrees
How do you test for chlorine gas?
Bleaches damp blue litmus after making it red as chlorine is acidic
What do halogens make when reacting with hydrogen
and example
Hydrogen halides which are soluble in water to form acidic solutions
eg) Hydrochloric acid
What is the balanced equation for the formation of a common hydrogen halide
H2 + Cl2»_space;»» 2HCl
What do halogens make when reacting with a metal
They react vigorusly to make a metal halide which is often with group 1 eg) sodium chloide
- Halogens higher up on the group react easier as they attract an outer shell electron more easily
What is a balanced equation for the formation of a metal halide (sodium chloride)
2Na + Cl2»_space;»> 2NaCl
What is a chemical property of a hydrogen halide
Soluble in water
HCl is aqueous
How can the reactivity of a halogen be worked out from displacement reactions
A more reactive halogen will displace a less reactive one from a compound
Describe what you would see if you added chlorine water to a potassium bromide solution
The more reactive chlorine would displace the bromine to make potassium chloride making the solution orange leaving it as excess in solution
Why is a displacement reaction a redox reaction
Because the halogens are reduced and gain electrons whilst halide ions are oxidised and lose electrons
Halide ion = The salt solution
Halogen = is the halogen being added
What is the ionic equation for chlorine displacing
bromine
Cl2 + 2Br-»_space;»> Br2 + 2Cl-
How could you show the reactivity trends of halogens
add halide salt solution to test tube and add halogen
and if colour change then displacement reaction has occurred.
Why are noble gases inert?
Because they contain a full outer shell of electrons so they dont easily give up or gain electrons
Name some properties of group 0
Colourless gases at room temperature
Monotomic - single atoms not molecules
Non-flammable
what is the trend for boiling and melting points going down group 0
increases
what is the trend for density going down group 0
increases
Name some everyday uses of Noble gases
- Argon is used in filament bulbs as its non-flammable
- Kypton and xenon are used in flash photos to stop flash burning up
- Argon and helum protect metals that are being welded to create inert atmosphere that doesnt react with oxygen
- Helium is used in airships and balloons as it has a density lower than air so can float (doenst ignite unlike hydrogen)