WHAT? WHY? HOW?

1.What makes the Earth rotate?

All celestial bodies in the universe were formed by the condensation of a rotating mass of gasses. The frictional and other forces in space are very small, hence due to the conservation of angular momentum (which states that in the absence of net external torque acting on a system about a given axis, the total angular momentum of the system about that axis remains constant), all celestial bodies along with Earth kept on moving about their axis as they started initially.

2.How does the sun tan our skin?

Tanning is the body's way of protecting skin from deadly effects of sun’s harmful ultra violet (UV) radiations. When UV radiations penetrate to the lower layers of the epidermis, then the melanocytes get triggered to produce brown pigments called melanin that act as the UV adsorbent and protects the skin from deadly effects of these radiations. It is only the accumulation of these brown pigments that causes tanning.

3. Why do soap bubbles disappear after some time?

A soap bubble is formed from soap and water. So, when the water present in the bubble gets soaked up by the dry air around it or gets evaporated then the skin of the bubble keeps on getting thinner and thinner and finally causes the bubble to pop.