The total mass increases. The total mass decreases. The total mass remains the same. Part of the mass is changed to heat energy.
When a mixture of oxygen and hydrogen is ignited in a test tube, the reaction shown occurs. Hydrogen + Oxygen -> Water + Energy What happens to the total mass of the contents of the test tube?

Options:
- The total mass increases.
- The total mass decreases.
- The total mass remains the same.
- Part of the mass is changed to heat energy.

The total mass remains the same.