Chemical changes Flashcards
What are the physical properties of the alkali metals?
They are all silvery solids
They have low density
They are soft metals
They have low melting and boiling points
What are the chemical properties of the alkali metals?
They are very reactive (increases as you go down the group)
They are stored in oil to prevent them from reacting with the oxygen in the air
They are silvery in colour but as they react with oxygen they quickly become dull
Why does reactivity increase as you go down group 1?
As you go down the group, the electron in the highest energy level gets further away from the nucleus. This means that the attraction between the nucleus and the electron in the highest energy level decreases and so the electron is more easily lost
What is the word equation for a metal reacting with water?
Metal + water → metal hydroxide + hydrogen
What is the word equation for a metal reacting with oxygen?
Metal + oxygen → metal oxide
What will you observe when lithium reacts with:
Oxygen
Chlorine
Water?
Oxygen - burns with a red flame to give a white solid
Chlorine - burns to give a white solid
Water - fizzes and moves on the surface
What will you observe when sodium reacts with:
Oxygen
Chlorine
Water?
Oxygen - burns with a yellow/orange flame to give a white solid
Chlorine - burns to give a white solid
Water - fizzes a lot and moves on the surface, melts, may catch fire with a yellow/orange flame
What will you observe when potassium reacts with:
Oxygen
Chlorine
Water?
Oxygen - burns with a lilac flame to give a white solid
Chlorine - burns to give a white solid
Water - fizzes a lot, melts, catches fire with a lilac flame
What are the properties of the halogens?
All non-metal
All covalently bonded diatomic molecules at room temperature
They all have coloured vapours (F pale yellow, Cl green, Br orange, I purple)
Low melting and boiling points (increases as you go down the group)
Poor conductors of heat and electricity
Low density
Dull
Why does reactivity decrease as you go down group 7?
Because group 7 reacts by gaining an electron in their highest energy level. As you move down the group, the highest energy level is further from the nucleus and there is less attraction from the nucleus pulling electrons into the atom
What are the properties of the noble gases?
Very unreactive because they have a full highest energy level, making them stable (inert)
They are non-flammable
At room temperature they all exist as colourless monatomic gases
Boiling point increases as you go down the group
What are the properties of the transition metals in comparison to the alkali metals?
Have higher melting and boiling points
Have higher densities
Are harder and stronger, therefore more difficult to break (used in construction)
Much less reactive and don’t react as quickly with oxygen and water
Most transition metals form a coloured compound
Many transition metals are used as catalysts
Many transition metals have ions with different charges
What is the word equation for a metal reacting with acid?
Metal + acid → salt + hydrogen
The name of the salt produced is related to the types of metal and acid that are used e.g. _______ chloride / sulphate / nitrate
What is the equation for a metal oxide reacting with acid?
Acid + metal oxide → salt + water
What happens in a displacement reaction?
A more reactive metal displaces a less reactive metal from its compound e.g.
Magnesium + copper sulphate → copper + magnesium sulphate
In a displacement reaction, the more reactive metal ends up with the compound
Displacement reactions release a lot of energy
