Ask Mr Brain...all will be explained

Mountains are nearer to the sun, but why is the temperature on a mountain top lower than that at sea level? Although mountains are slightly closer to the sun, temperatures have little to do with proximity to the sun. The earth is about 150 million kilometres from the sun, so even a Himalayan mountain's 8,000 metres is an insignificant distance. It is the air - or lack of it - that makes places at high altitudes much colder than those at lower altitudes.

The air is thinner at high altitudes and cannot trap a lot of heat. Heat from the sun disperses very quickly so temperatures remain low. For every 100 metres increase in altitude, the temperature drops by 0.6 degrees Celsius.

At sea level, the air is much denser and heat is easily trapped. As a result, temperatures at low altitudes are higher.

Why do two balloons that have just been rubbed with a wool cloth move away from each other? All matter contains positively charged particles called protons and negatively charged particles called electrons.

Some substances, because of the nature of their atoms, lose electrons when rubbed and become positively charged.

Other substances gain electrons easily and become negatively charged. Like charges repel and opposite charges attract.

When a balloon is rubbed with a wool cloth, the wool loses some of its electrons. The balloon gains electrons from the cloth and is negatively charged.