section_heading: Kemijska
paragraph_text: HC ≡ CH  +   Br<sub>2</sub>   &rarr;   HC = CH                           |   | Br Br  HC = CH   +   Br<sub>2</sub>   &rarr;   HC - CH   |   |                   |   | Br Br                  Br<sub>2</sub>  Br<sub>2</sub>