II. Define the following terms:
1. Physical changes
2. Chemical changes
5. Endothermic changes
3. Pasteurisation
16
21
4. Fermentation
18
Answers
Answer:
A physical change is a change to the physical—as opposed to chemical—properties of a substance. They are usually reversible.
A change in which one or more new substances are formed is called a chemical change. A chemical change is also called a chemical reaction. Examples are burning of any substance, rusting of iron.
An endothermic reaction is any chemical reaction that absorbs heat from its environment. The absorbed energy provides the activation energy for the reaction to occur. A hallmark of this type of reaction is that it feels cold. A good example of an endothermic reaction includes dissolving a salt.
Pasteurization or pasteurisation is a process in which packaged and non-packaged foods (such as milk and fruit juice) are treated with mild heat, usually to less than 100 °C (212 °F), to eliminate pathogens and extend shelf life.
Fermentation is defined as a process involving yeasts or other microorganisms breaking down a substance, or a state of excitement. When grapes are crushed or transferred into a press, cultured yeast is added, and the sugars in the grapes start to convert into alcohol, this is an example of fermentation.
Explaination:
1. physical changes- A change in which a substance undergoes a change in its physical properties is called a physical change.
Example is crystallisation.
2. chemical changes- Chemical changes occur when a substance combines with another to form a new substance, called chemical changes.
Example is Burning wood.
3. endothermic changes- Chemical reaction that is accompanied by the absorption of heat, or an organism that generates heat to maintain its temperature is called endothermic changes.
4. pasteurization- the partial sterilization of a product, such as milk or wine, to make it safe for consumption and improve its keeping quality.
5. fermentation- the chemical breakdown of a substance by bacteria, yeasts, or other microorganisms, typically involving effervescence and the giving off of heat.
hope it help you out.......☺️