It is very dangerous to sleep in an unventilated room with fire burning inside because the fire produces carbon monoxide and carbon dioxide gases. Carbon monoxide is poisonous gas and can cause of death.
Diamonds shines at night because due to high refractive index of the diamond the rays of light get internally reflected.
It is hotter on a cloudy night than on a clear night because clouds prevent the heat radiated by the Earth from escaping into the sky.
Leaves are green in color because they contain chlorophyll.
Food is cooked quickly in pressure cooker because the boiling point of water increases at high pressure. Food cooks faster at high temperature as compare to use normal vessel.
It is easier to swim in sea water than in river water because density of sea water is higher than river water.
White roof keeps the house cooler in summer then black roof because white roof reflects more and absorbs less heat rays whereas black roof absorbs more and reflects less heat rays.
Petrol fire does not get extinguished by throwing water on it because heat of the petrol fire is so intense that water thrown on it gets evaporated and decomposed. Hence, it is not effective in extinguishing the petrol fire.
In deserts, day temperatures are very high and night temperatures are extremely low because the specific heat of sand is very low. Therefore, it absorbs the heat readily and its temperature rise by a large degree during the day. At night sand radiates the heat equally readily, making the temperature low.
Water from a hand pump is warm in winter and cold in summer because in winter outside temperature is low and in summer outside temperature is higher as compared to temperature of water obtained from underground which remains practically unchanged due to Earth being bad conductor of heat.
When a gun is fired at a visible distance, the sound is heard a little after the smoke is seen because the velocity of light is much higher than that of sound.
Red flower looks red because except red color it absorbs all other colors of light.
What is Science Behind, Why its happens, How is it ??