NCERT Solutions for Class 9th Science Chapter 8 .4 Symbols of Elements — Pause and Ponder

Book page 1498 Updated on2026-09-08

Q8.

Imagine you are a scientist who has discovered a new element. Name this element after yourself and justify that the symbol you have chosen follows the IUPAC rules.

Answer

This one is yours to invent, so here is a worked model you can copy the reasoning from.

Sample answer: I name the element Anandium, after myself, with the symbol An.

Justification against the IUPAC norms given in the chapter:

Rule	Does “An” obey it?
The symbol is the first letter, or the first two letters, of the name	Yes — Anandium
First letter capital, second letter (if any) small	Yes — A capital, n lowercase. Not AN, not an
The symbol must not already be taken	Checked — An is not the symbol of any of the 118 known elements
Names of elements named after a person end in -ium	Yes — Anand + ium = Anandium, like Curium and Einsteinium

If “An” had already been in use, the third IUPAC norm allows a letter from later in the name instead of the second — for example Ad (from Andium) or Am. That is exactly how chlorine got Cl and zinc got Zn.

Tip: IUPAC — the International Union of Pure and Applied Chemistry — is the body that actually approves names and symbols. Real elements are named after places (Polonium, Nihonium), scientists (Bohrium, Meitnerium) or properties, and no element may be named after a living person's own request.

Q9.

What problems could arise if every scientist used different symbols for the same element?

Answer

Chemistry would stop being a shared language, and the errors would start at the very first step of every calculation.

Formulae would become ambiguous. If one chemist wrote Na for sodium and another wrote S for sodium, then “SO” could mean sodium oxide or sulfur monoxide. There is no way to tell from the paper alone.
Equations could not be balanced or checked by anyone else, so results could not be reproduced — and reproducibility is what makes a claim scientific.
Numerical work would go wrong. Mistake sulfur (mass ≈ 32 u) for sodium (≈ 23 u) and every mass calculation in the experiment is wrong.
Language barriers would return. Iron is loha in Hindi, fer in French, Eisen in German — but Fe everywhere. A single symbol lets a chemist in Chennai read a paper from Japan.
Safety would suffer. A chemical drum, a medicine label or a factory sign must be readable by any trained person, immediately and without doubt.

Why it happens: a symbol is not a decoration; it is a piece of data that gets used in a calculation. Standardising it is exactly like standardising SI units. That is why the naming of elements was handed to one international body, IUPAC, instead of being left to individual scientists.

Did you know? Dalton's 1803 pictorial symbols — a circle with a dot for hydrogen, a filled circle for carbon — were a real attempt at a standard, but they were hard to print and hard to remember. Berzelius replaced them in 1813 with letters taken from Latin names, which is the system we still use.

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