WHAT? WHY? HOW?

1. Why does a deodorant always feel cold to us?

Deodorants contain low boiling point compounds like ethanol, which when come in contact with our skin, evaporate quickly by taking the required latent heat of vaporisation from the skin making it feel colder. Also, when the deo is sprayed, its contents come out from high pressure area to the low pressure area. As the temperature is directly proportional to the pressure so temperature also decreases due to the decreased pressure.

2.Why do popcorns become soft after popping?

Each kernel of popcorn contains soft starch along with some water

surrounded by a hard layer of endosperm, which is a food storage tissue. When the popcorn is heated, the water in the endosperm turns into steam and start building the pressure inside the kernel. When the pressure gets high enough, the kernel explodes and turns inside out. The starch inside the kernel becomes soft like gelatin and puffs out making the hard, inedible kernel to a fluffy, edible snack.

3. Why does hot water remove the greasy stains easily?

Hot water increases the energy of the fat molecules causing them to vibrate faster due to which their bonds get weakened and turns the fats into a liquid which easily gets washed away with the running water.

4. Why are we breathless after running or walking faster?

During any physical work like

running, walking faster, exercise etc. our body muscles need more

energy, so more of the oxygen is required to burn up the glucose to produce energy. Hence we breathe faster to take in more oxygen to fulfill the energy requirement by the muscles.