The electronic configuration of noble gases are given in the table. Element Atomic number Electronic configuration Helium He 2 2 Neon Ne 10 2 , 8 Argon Ar 18 2 , 8 , 8 Krypton Kr 36 2 , 8 , 18 , 8 Xenon Xe 54 2 , 8 , 18 , 18 , 8 Radon Rn 86 2 , 8 , 18 , 32 , 18 , 8 How many electrons are present in the outermost shell of these elements except in the case of helium?

All noble gases except helium has eight electrons in their outermost shell. That is, they have a stable octet electron configuration and in the case of helium, it has two electrons in its outermost shell. That is, it has a duplet electron configuration.

Analyse the electronic configuration of the elements given in the table. Element Atomic number Electronic configuration Magnesium 12 2 , 8 , 2 Oxygen 8 2 , 6 Sodium 11 2 , 8 , 1 Chlorine 17 2 , 8 , 7 Do the elements in the given table have stability? Why? If not, how do they attain stability?

No, the elements in the given table are not stable. This is because, they do not have the stable octet electron configuration. The given elements can attain stability through chemical bonding. That is, atoms of these elements can attain eight electron configuration in their valence shell through chemical bonding.

E M B I B E

Chemistry Standard IX Part 1>Chapter 2 - Chemical Bonding>Exercise 1>Q •

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Why do atoms combine together?

Important Questions on Chemical Bonding

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Chemistry Standard IX Part 1>Chapter 2 - Chemical Bonding>Exercise 1>Q •

Do atoms combine in the same manner?

EASY

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Chemistry Standard IX Part 1>Chapter 2 - Chemical Bonding>Exercise 1>Q •

How are the atoms in molecules held together?

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9th Kerala Board

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Chemistry Standard IX Part 1>Chapter 2 - Chemical Bonding>Exercise 1

The electronic configuration of noble gases are given in the table.

Element	Atomic number	Electronic configuration
Helium $(He)$	$2$	$2$
Neon $(Ne)$	$10$	$2, 8$
Argon $(Ar)$	$18$	$2, 8, 8$
Krypton $(Kr)$	$36$	$2, 8, 18, 8$
Xenon $(Xe)$	$54$	$2, 8, 18, 18, 8$
Radon $(Rn)$	$86$	$2, 8, 18, 32, 18, 8$

How many electrons are present in the outermost shell of these elements except in the case of helium?

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Chemistry Standard IX Part 1>Chapter 2 - Chemical Bonding>Exercise 1

What is the maximum number of electrons that can be accommodated in the outermost shell of an element?

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Chemistry Standard IX Part 1>Chapter 2 - Chemical Bonding>Exercise 1>Q •

Analyse the electronic configuration of the elements given in the table.

Element	Atomic number	Electronic configuration
Magnesium	$12$	$2, 8, 2$
Oxygen	$8$	$2, 6$
Sodium	$11$	$2, 8, 1$
Chlorine	$17$	$2, 8, 7$

Do the elements in the given table have stability? Why?
If not, how do they attain stability?

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Chemistry Standard IX Part 1>Chapter 2 - Chemical Bonding>Exercise 1>Q •

You are familiar with the compounds formed by the elements like magnesium, oxygen, sodium and chlorine, aren't you? Write the names of few compounds. How are the atoms in these molecules held together?

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Chemistry Standard IX Part 1>Chapter 2 - Chemical Bonding>Exercise 1

What are the atoms that combine to form sodium chloride?

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Chemistry Standard IX Part 1>Chapter 2 - Chemical Bonding>Exercise 1>Q •

How many electrons are there in the outermost shell of sodium atom?