Question

5. How do you know when a chemical reaction has taken place?

OB. formation of a gas
O D. all of the above
O C. solid substance is produced
O A. heat and light are produced

Answer 1

You can determine if a chemical reaction has taken place by observing signs such as the formation of a gas, the formation of a solid substance, and the production of heat and light.

Step-by-step explanation:

In Chemistry, you can determine that a chemical reaction has taken place by observing certain signs. These signs include:

1. Formation of a gas: If a gas is produced during the reaction, it indicates that a chemical change has occurred. An example is the reaction between baking soda and vinegar, which produces carbon dioxide gas.
2. Formation of a solid substance: When a solid is formed during a reaction, it indicates a chemical change. For example, the reaction between calcium chloride and sodium phosphate results in the formation of a solid precipitate.
3. Heat and light production: Some chemical reactions release energy in the form of heat and/or light. An example is the combustion of wood, which releases heat and light.

These signs serve as evidence that a chemical reaction has occurred and can be useful in identifying the occurrence of such reactions.

Learn more about Signs of a chemical reaction