Story by Ms. Rani Subramaniam
It was a hot summer day.
Ram and Shyam were rather thirsty.
“Amma is there some cold water? “, they asked their mother.
“Sorry, just drink some water that is at room temperature “, mother said.
Mother believed that drinking cold water was not such a good idea, as it did not aid digestion.
Ram and Shyam drank some water,but filled up a glass bottle completely with water, closed it nicely with a lid.
They thought they would drink really cold water a little later.
They then put the bottle in the freezer compartment of the fridge.
Mother did not like plastic bottles.
She said that they take years to degrade and that we spoilt nature by using them.
Ram and Shyam forgot about the bottle.
A day later when they opened the freezer compartment for some reason, they found that the bottle of water that they had put in was frozen. Not only that, the bottle had burst too!
It was not their fault she said as they did not know the science behind it.
“What is the reason for the broken bottle?“,asked Ram and Shyam simultaneously.
“Well!”, mother said, “almost all liquids contract on freezing. “
Water is very different.
It is a rare liquid that expands on freezing.
This fact is amazing, as it saves marine life.
“How is that?”, asked Ram and Shyam.
“When the surface of a pond or lake or sea freezes in winter, it expands, becomes less dense than water and stays on top.”
“The lower layers of the lake or pond or sea does not freeze. Summer arrives even before there is any possibility of the lowermost layers freezing.”
“Thus, sea creatures are not frozen to death.”
“For any other liquid, the surface layer freezes, contracts, becomes dense, and sinks.
The freezing happens bottom upwards.”
“For water, the freezing happens top downwards.”
Every little issue is taken care of.
Yet we so mindlessly spoil nature without thinking.
Mother also mentioned that in places that are very cold, the water pipes outside homes burst.
“Why does that happen?, asked Ram and Shyam.
Mother said, “That is something I will leave for you to find out!”
Homework:
At what temperature is the density of water maximum?
What happens to water when the temperature of water goes below 4 degree Centigrade?
Nature takes care of sea creatures. Are we killing them by disposing harmful waste into the sea? Think about all the creatures that die because they have swallowed plastic bottles and other material which we so mindlessly throw into the ocean.