Answer: 1) A) highly active metal
2) A) Chemical energy is changed to a electrical energy.
3) B) paste
Step-by-step explanation: 1. Oxidation is defined as the process in which electrons are lost. More active metals are the metals which can easily lose electrons and thus highly active metals are most easily oxidized.
2. Electrochemical cells are those cells in which chemical energy is used to generate electrical energy.
For example: dry cells and batteries.
The metal electrodes are dipped in their respective salt solutions and are connected by a salt bridge. The anode undergoes oxidation and loss of electrons take place which are transferred through external wire to the cathode where reduction or gain of electrons take place and thus electricity is generated.
3. Dry cell is an electrochemical cell which converts chemical energy to electrical energy and the electrolyte used is semi solid form or in paste form so as to avoid spillage of electrolyte.