Question

Classify the glowing of an electric bulb is physical or chemical change.

Answer 1

• Physical change: A change that alters some specific property of matter without any change in the composition of its molecules is called a physical change.
• No new substances are formed during physical change.
• Physical changes can be generally reversed.
• There is no change in weight during physical change.
• Only a little heat is absorbed or given off during a physical change.

When electricity is applied to the tungsten bulb, electrons in the atoms become excited and release energy in the form of photons. As a result, there is no chemical reaction. It's a physical reaction.

Hence, it is a physical change.