Question

Which of the following is an example of a physical change? A) grinding coffee beans B) baking a cake C) converting water to hydrogen and oxygen D) digesting a cheeseburger E) burning coal

Answer 1

Grinding coffee beans is an example of a physical change, where the appearance of the substance is altered but its chemical identity remains the same.

Step-by-step explanation:

The question asks which of the following is an example of a physical change. Among the options provided, grinding coffee beans is an example of a physical change. A physical change refers to a change in which the form of matter is altered but one substance is not transformed into another. Grinding coffee beans changes their size and shape but doesn't change the chemical identity of the coffee itself. In contrast, the other options involve chemical changes where the substances are changed into new substances with different chemical properties.

Answer 2

Answer: A) grinding coffee beans

Step-by-step explanation:

A physical change is defined as a change in which there is alteration in shape, size etc. No new substance gets formed in these reactions.

A chemical change is defined as a change in which a change in chemical composition takes place. A new substance is formed in these reactions.

1. Grinding coffee : Only change in size takes place, thus a physical change

2. Baking a cake: the chemical reaction occurs by combination of flour with oxygen , thus a chemical change.

3.:converting water to hydrogen and oxygen: The decomposition iof water takes place, thus is a chemical change

4.Burning of coal: the chemical reaction occurs by combination of carbon with oxygen , thus a chemical change.