“Rani di, give me some echtoO” said Ammu, putting her school bag on the rack and walking straight to the kitchen.
‘’Appu, Ammu…you first go for a wash, change your clothes and come. I’ll keep your echtoO and snacks ready..” said the mother.
Ammu was a brilliant, naughty girl studying in class 3. Her teacher had talked about the formula of water in the class, so she tried using it with their domestic helper, Rani. Appu her elder brother- a true companion in all crimes, studied in class 7 in the same school.
“Rani, please keep their snacks, milk and water ready..by that time I will finish this ironing”, Ammu’s mother said.
“She has asked for something else memsaab…echto”, replied Rani.
“Not echto, it’s H 2 O didi, I asked for H 2 O…” Ammu said with a naughty smile.
“Give her water didi. She is asking for water”, Appu joined in.
“Water? ECHTO????”- an astonished Rani shook her head.
“Not echto….H 2 O. Water is hydrogen gas and oxygen gas combined together in the ratio 2:1”, Appu tried educating Rani by sharing the chemical composition of water.
And Rani escaped to the kitchen singing echto echto echtoo.
“Appu, you said hydrogen gas and oxygen gas??” asked Ammu.
“Yes, water is made up of hydrogen gas and oxygen gas” replied Appu.
“Hydrogen gas?? You mean the gas we made during our last vacation and filled in the balloon?”, asked a surprised Ammu.
Appu and his friends had tried an experiment with aluminium foil (he got after buttering Rani) and milk of lime, that Golu- his friend, managed to get from the whitewashing labourer.
“Yes” came Appu’s reply.
“We breathe oxygen, isn’t it? But in water, we can die from suffocation. The hydrogen balloon you made flew away, but water doesn’t fly. Hydrogen and oxygen are gases, water is a liquid. Hey, you are lying bhaiyya..water can’t be made out of hydrogen and oxygen” Ammu taunted.
“It is made of hydrogen and oxygen that’s why its called H2O.” Appu wasn’t ready to lose to his sister.
“Then bhaiyya, when we make lemon juice we add lemon water and sugar…it is sweet like sugar, sour like lemon, and liquid-like water too. So water should fly like hydrogen and should support burning like oxygen if it’s made out of hydrogen and oxygen…is it not? So now what to do??” Ammu was quite successful in triggering Appu.
Appu took his laptop, googled for properties of hydrogen and oxygen as well as water. “Look..what I said is right”, Appu showed Ammu and continued explaining. “Water is made from two atoms of hydrogen bonded to one atom of oxygen. At room temperature, hydrogen and oxygen are both colorless, odorless gases, and they remain gases down to extremely low temperatures. Water, however, is a liquid, at temperatures up to 100°C (212°F) and a solid below 0°C (32°F). But the answer to your question is not here, let’s ask mom.”
Both ran to their mother. Ammu started elaborating her doubt, starting from preparing a lime juice “Amma, why does water not show the properties of hydrogen or/ and oxygen?”
“That’s our doubt”, an impatient Appu interfered.
“In lime juice, we just mix sugar, water and lemon juice. But by mixing hydrogen and oxygen, we can’t get water babe”, the mother tried to explain.
“Oh…yes, yes. Air is a mixture of nitrogen, oxygen, hydrogen, carbon dioxide….that’s why air supports combustion”, Appu smartly remarks.
“And we breathe air” says Ammu.
“Yes, of course” mom nodded. “If we just mix…properties of individual substances are shown by the mixture. But if the elements are chemically combined, a new substance would be formed, and they will not show the properties of constituent elements.”
“So in water hydrogen and oxygen are chemically combined” added Appu.
“What’s that?” asked Ammu, visibly confused.
“It means hydrogen and oxygen are joined together in water. Your teacher told H2O, no? Two hydrogen atoms hold one oxygen. They hold each other so tightly that they can’t move apart from each other, and also they can’t show the properties of either of them. We say that hydrogen and oxygen are elements, and water is a compound. Compounds will not show properties of elements.” replied Appu.
“Oh, that’s why table salt doesn’t catch fire in water?”, Ammu asked looking at her mother, as she stood perplexed and Appu seemed very confident.
“Yes, sodium will catch fire in water. But sodium chloride- table salt, which is a compound, does not. Do you remember, you had read in the newspaper about leakage of chlorine from the tanker, and people suffered suffocation? That’s because chlorine is a poisonous gas that causes suffocation. But without table salt we can’t make anything tasty, you know. Chlorine as well as sodium have lost their properties in sodium chloride. Ammu, you would understand it better when you read more as you grow up. Now have your snacks and play outside” said the mother.
“Gudiya aap ki H2O rakha hai”, Rani said, as she kept a glass of water on the table.
From now Rani would never call it water again. And the mother was sure that her little doll wouldn’t leave any “substance” from her mind!