Methods of Separation in Everyday Life

After threshing, Keshav and Rukhsar are helping their uncle separate the light husk from the wheat grains by dropping the mixture from a height. Keshav says they should wait for a completely still day, so that everything falls straight down neatly. Rukhsar says they need a gentle breeze for this to work at all. Who is right?

Tenzin's grandmother sieves wheat flour before making rotis, and flakes of bran stay behind in the sieve. Tenzin says the sieve separates things by size — anything bigger than the holes stays back. His friend Yamini says it separates them by weight — heavy bits stay back and light bits fall through. Whose explanation is correct?

After heavy rain, the water from Shreyas's tap comes out muddy. He fills a bucket, lets the mud settle at the bottom for an hour, then carefully pours the clear water from the top into a jug. Shreyas says the water is now safe to drink because it looks perfectly clear. Anvi says looking clear does not mean it is safe to drink. Who is right?

On a trip to the salt pans near Thoothukudi, Pallavi explains that salt is made by leaving seawater in shallow beds under the sun until the water evaporates. Joseph says that's far too slow — it would be quicker to pour the seawater through a fine cloth and collect the salt left on the cloth. Whose method will actually give salt?

Veer watches his mother churn curd with a wooden madhani until lumps of white butter float to the top. Veer says the butter was already hidden in the curd, and churning only separated it out. Hiral says churning turned part of the curd into a new substance called butter. Who has understood it correctly?

In the school lab, a box of fine iron filings has spilled into a tray of fine sand, and the grains of both are about the same size. Nirmal says the quickest way to separate them is to shake the mixture through a sieve. Dhruv says a sieve won't help here — they should use a magnet. Whose plan will work?