b) electric current

e) current as the movement of electrons in metals and movement of ions in electrolytes

b) conventional current and electron flow

electric current is the movement of electrons in metals

• most electrons in metals are fixed to their atoms, but some are free to move

• metals are structured as a lattice of positive ions surrounded by delocalised electrons

it is also the movement of ions in electrolytes

• electrolytes are molten or aqueous ionic solutions

• the electrolyte separates into positive and into negative ions, which are attracted to the cathode and the anode

• conventional current represents electric current as travelling from the positive to the negative terminal

  • electric current in metals always travels from the negative to the positive terminal, opposite to the conventional current

  • electric current in electrolytes can travel from the negative to the positive or from the positive to the negative terminal, either in the same direction or opposite to the conventional current