When a sodium chloride solution is electrolysed, what is produced at the negative electrode?
Hydrogen
When lead bromide is electrolysed, what is formed at the positive electrode?
Bromine
Combustion and neutralisation are examples of what sort of reaction?
Exothermic
If a reaction takes in energy from its surroundings, it is…
Endothermic
If a reaction releases energy into its surroundings, it is…
Exothermic
What ions does an alkali produce in aqueous solutions?
OH⁻
What ions does an acid produce in aqueous solutions?
H⁺
Which one of the following substances conducts electricity?
Graphite
How many bonds does each carbon atom have in diamond?
4
Why can molten ionic substances conduct electricity?
The ions are free to move
What type of bonding is present in graphite?
Giant covalent
Non-metal + non-metal → what type of bonding?
Covalent
Metal + non-metal → what type of bonding?
Ionic
What is the mass number of an element?
Protons + Neutrons
