- Zinc chloride and hydrogen gas are new substances
- Hydrochloric acid combing with zinc forms zinc chloride
- Hydrochloric acid combing with zinc forms hydrogen gas
- Therefore, hydrochloric acid combing with zinc forms new substances

- Hydrochloric acid combing with zinc forms new substances
- Chemical reactions cause new substances to form
- So, hydrochloric acid combining with zinc is an example of chemical reaction

So, hydrochloric acid combining with zinc is an example of chemical reaction
Question: Hydrochloric acid is added to a beaker containing a piece of zinc. As a result, zinc chloride is formed and hydrogen gas is released. This is an example of
Context: - Zinc chloride and hydrogen gas are new substances 
- Chemical reactions cause new substances to form 
- Hydrochloric acid combing with zinc forms zinc chloride 
- Hydrochloric acid combing with zinc forms hydrogen gas