Important Scientific Reasoning Everyday Science - 2

Why the green house operators paint their glass roofs white in summer?

Ans: White colour is the reflector of light and it absorbs less heat as compared to other colours. As in summer there is already very hot season and heat is not required to that level. That is why the green-house operators paint glass roofs white in summer season.

Water boils quicker on mountains.

Ans: On Mountains the pressure of the air is low due to height, as the air pressure decreases with altitude. In this way, water boils quicker on mountains at temperature less than 100 degree centigrade, which is the boiling point of water at ground level.

Rainbow is produced in the sky after rainfall and sunlight.

Ans: After rain, many droplet of water travel in the atmosphere. When sun rays fall on these droplets, dispersion of water occurs and droplets act as prism and produce a spectrum of seven colours. That’s why a rainbow is seen in the sky after rain.

Milk is considered as an ideal food.

Ans: Milk is considered as an ideal food due to following reasons: a) It contains all constitute of balanced diet.

Milk contains fat.

Milk has high nutritional value because it contains proteins as well as minerals.

Lunar eclipse last much longer than solar eclipse.

Ans: Lunar eclipse last longer than the solar eclipse because the length of the earth’s umbral shadow cone is more than three times the average distance between the moon and the earth, so the shadow is relatively wide at the point where the moon crosses it.

Goitre is common in hilly areas.

Ans: Goitre is common in hilly areas because there is deficiency of Iodine in the water.

Detergents are better cleaning agents.

Ans: A detergent consists of hydrophilic and hydrophobic ends. In case of dirt the detergent pushes the dirt off the wet surface of the fabric. The washing machine provides the agitation.

Decomposers are important for life.

Ans: Decomposers break down animal waste and dead organisms in order to get energy and release free nutrients back into the ecosystem. 

OR

Decomposers break down organics into nutrients, which can be used by living organisms to create new life.

Places near sea are cooler in summer.

Ans: Sea water keeps the temperature moderate. In the summer season the places located near sea are cooler due to the lower temperature of water.

Colour blindness is more common in men than women.

Ans: Women have the sex chromosomes XX, while men have the chromosomes XY. The gene for normal colour vision is found on the X-chromosome. If a woman has one X-chromosome with the gene and one without it, she will not be colour blind. On the other hand, a man with an X-chromosome that is missing the gene has no 'backup'. He will definitely be colour blind. Colour blind women have both X-chromosomes missing the colour vision gene. This is less probable mathematically than having just one X-chromosome missing the gene.