When a cell goes dead

The idea

Over time the chemicals in a cell get used up and it stops working; it is then called dead and cannot supply any more electricity.

A torch that stops

A torch works well for days. Then one day the lamp will not glow, even though the bulb is fine.

What do you think has happened to the cell?

• Its chemicals have been used up
• It gained extra chemicals
• It was never a cell

Run the cell

Let the lamp run for a while, again and again, until the cell stops working.

Used up

A cell makes electricity from the chemicals inside it. As the lamp ran, the chemicals got used up. When they were finished, the cell stopped working.

Over time the chemicals in a cell get used up, and the cell stops working. It is then called dead and cannot supply any more electricity.

Notes

The chemicals in a cell get used up over time. The cell then stops working. It is called dead and cannot supply any more electricity.

Check yourself

A cell stops working because …

A cell that cannot supply any more electricity is called …

A cell is dead. What happens to the lamp it was lighting?

What does a cell use to make electricity?

• it has too much electricity. A cell stops when its chemicals are used up.
• the lamp is too bright. The lamp has nothing to do with it. The chemicals in the cell run out.
• its chemicals have been used up — correct. Yes!
• dead — correct. Yes!
• charged. A dead cell has no chemicals left to make electricity.
• rechargeable. Being dead is different. A dead cell cannot supply electricity any more.
• The lamp glows brighter. A dead cell cannot supply any more electricity.
• The lamp goes off — correct. Yes!
• The lamp glows the same. With no electricity from the cell, the lamp goes off.
• The lamp. The lamp uses electricity. It does not supply it.
• The switch. A switch only turns the current ON and OFF.
• The chemicals inside it — correct. Yes!