Explanation
No new substances are formed when wax melts. This is a physical change. However, if the wax burns, it is a chemical change. The question here is associated with melting, and so the answer is 'physical' change.
Rust is also called hydrated iron oxide. It is, therefore an oxide of iron.So, correct option is B.
Photosynthesis is the process used by plants to produce their food. In this process, light energy is converted into chemical energy.
The chemical reaction which takes place in photosynthesis involves combining of water and carbon dioxide to form glucose and oxygen. Since new chemical species are formed, photosynthesis is clearly a chemical change.
Which of the following is a feature of physical change?
A physical change is any change in matter that involves the substance going from one physical state to another.
It does not lose its original properties because no new formation takes place when changing from one phase to another.
A substance can go from a solid to a liquid, a liquid to a gas, a gas to a liquid, a liquid to a solid, a solid to a gas, or a gas to a solid.
Hence, option D is correct.
Pick out the chemical change from the following.
A change in which the form of matter is altered but one substance is not transformed into another is called:
When magnesium ribbon burns, it reacts with the oxygen present in the air and form a powdery ash called magnesium oxide.
$$2Mg+O_2\rightarrow 2MgO$$.
Hence option B is correct.
Please disable the adBlock and continue. Thank you.
