Introduction: Plastic is a type of polymer material that is known for its non-conductive properties. It is used in a wide range of applications, from electrical insulation to packaging. However, when water is kept in a plastic bottle under the sun, it tends to heat up. This seems to contradict the insulating properties of plastic. In this article, we will explain why this happens.

Plastic as an Insulator: Plastic is an insulator because it does not allow the flow of electrons or electric current. This means that it does not conduct heat or electricity. As a result, it is used in electrical insulation, where it prevents the flow of electricity and reduces the risk of electrical shocks.

Why Water Heats Up in a Plastic Bottle: While plastic is an insulator, it is not a perfect insulator. It still allows some heat to pass through it. When a plastic bottle is kept under the sun, the sunlight passes through the plastic and heats up the water inside. This happens because:

- Plastic is transparent: Most plastics are transparent, which means that they allow sunlight to pass through them. Sunlight contains a lot of energy, and when it hits the water inside the bottle, it heats it up.

- Plastic absorbs heat: While plastic does not conduct heat, it does absorb heat. When the plastic bottle is under the sun, it absorbs some of the heat energy from the sunlight and transfers it to the water inside.

Conclusion: In summary, plastic is an insulator, but it still allows some heat to pass through it. When water is kept in a plastic bottle under the sun, the plastic allows sunlight to pass through it and absorb some of the heat energy from the sunlight. This results in the water heating up.

As plastic is insulator of electricity but it is bad conductor of heat so water kept in a plastic bottle heats up when kept under the sun .