| 1 | Next, chlorine is added. | |
| 2 | The reaction is highly exothermic and produces chlorine, a highly dangerous gas. | |
| 3 | Try to find paper products that are made with recycled materials and are chlorine-free. | |
| 4 | And that is an Erlenmeyer flask that has been filled with chlorine and sodium has been added to it. | |
| 5 | Maybe chlorine is not the best choice for disinfecting swimming pools. |