Groups in the periodic table Flashcards
Properties of group 1 metals
- Low density
- Only shiny on the inside
- Low melting and boiling points
- Soft-they can be cut with a knife
What are group 1 metals known as
Name them
‘Alkali metals’
Lithium, Sodium, Potassium, Rubidium, Caesium and Fracium
How many outer electrons do they have
Alkali metals
1 beacuse they are in group 1 so they also have similar chemical properties
What do alkali metals form?
The alkali metals form ionic compounds
Are group 1 metals reactive and why?
They are very reactive they readily lose their single outer electron to form 1+ ion with a stable electronic structure
The more readily a metal loses its outer electrons, the more reactive it is
As you go down group 1 do the metals get more reactive?
Why or how
As you go dowm group 1, the alkali metals get more reactive. The outer electron is more easily lost because its further away from the nucleus (the atomic radius is larger) so its less strongly attracted to the nucleus and less energy is needed to remove it.
When sodium reacts with chlorine it forms an ionic salt called sodium chloride
2Na + 2H2O ➔ 2NaOH + H2
Equation when they react with water
Alkali metal
Alkali metal + water ➔ metal hydroxide + hydrogen
What are group 7 metals called
Name them
‘Halogens’
Flourine, Chlorine, Bromine, Iodine, Astatine
How will group 1 metals react in water?
They react vigorously
Lithium will move around the surface fizzing furiously
Sodium and potassium do the same, but they also melt in the heat of the reaction
Potassium even gets hot enough to ignite the hydrogen gas being produced
They exist as diatomic molecules what does that mean?
Sharing one pair of electrons in a covalent bond giving both atoms a full outer shell
How many outer electrons do halogens have
7
Describe fluorine
Poisionous gas, yellow gas and very reactive
Describe chlorine
Poisionous gas, green gas and less reactive than fluorine
Describe Iodine
Iodine can form poisonous purple vapours, grey solid and is a antiseptic
Describe Bromine
Poisonous gas, red/brown liquid
As you go down does it get more reactive and why
Halogens
As you go down the series the reactivity decreases because it gets harder to fill the outer shell when the nucleus gets further away (atomic radius is larger)
When a halogen gains an electron whats it called
A metal halide
Halogens higher up in group 7 are more reactive because they can attract the outer electron of the metal more easily
What colour do halogens turn in water
Bromine water is orange
Chlorine water is colourless
Iodine water is brown
More reactive halogens will always displace less reactive ones
What are noble gases
They are a colourless gas which are are not flammable
What does a noble gas being inert mean
As they have full outer shells they are inert meaning they don’t really react with anything
Therefor they exist as single atoms
What colour are halides in water
Halide salts (e.g. KCl, KBr, KI) are colourless
Bromine water is orange
Chlorine water is colourless
Iodine water is brown
Do the melting and boiling points of the halogens increase or decrease as you go down the group?
Increase
Are noble gases flammable?
No
