Some compounds and their nature are shown in the table. Complete the table by finding out the electron negativity difference between the constituent elements. Compounds Difference in electronegativity of the constituent elements Nature of the compound Carbon monoxide CO 3 . 44 - 2 . 55 = 0 . 89 Covalent Sodium chloride NaCl Ionic Methane CH 4 Covalent Magnesium chloride MgCl 2 Ionic Sodium oxide Na 2 O Ionic

The tendency of an atom to attract the shared pair of electrons towards itself is called as the electronegativity. Using the Pauling's electronegativity scale, we can complete the following table as, Compounds Difference in electronegativity of the constituent elements Nature of the compound Carbon monoxide CO 3 . 44 - 2 . 55 = 0 . 89 Covalent Sodium chloride NaCl 3 . 16 - 0 . 93 = 2 . 23 Ionic Methane CH 4 2 . 55 - 2 . 20 = 0 . 35 Covalent Magnesium chloride MgCl 2 3 . 16 - 1 . 31 = 1 . 85 Ionic Sodium oxide Na 2 O 3 . 44 - 0 . 93 = 2 . 51 Ionic

Consider the hydrogen chloride molecule HCl . What is the electronegativity of hydrogen? What is the electronegativity of chlorine? The atomic nucleus of which of these elements has a greater tendency to attract the shared pair of electrons?

The tendency of an atom to attract the shared pair of electrons towards itself is called as the electronegativity. According to the Pauling's scale, the electronegativity of hydrogen is 2 . 2 . Chorine is a halogen and an electronegative non-metal. According to the Pauling's scale, the electronegativity of chlorine is 3 . 16 . Halogens are highly electronegative due to the high effective nuclear charge compared to hydrogen. Therefore, chlorine will have a greater tendency to attract the shared pair of electrons.

Complete the table given below analyse the change in the electronic arrangement of elements during the formation of each compound. Find how they are related to valency. Compounds Component elements Atomic number Electronic configuration Number of electrons transferred or shared or accepted Valency NaCl Na 11 _____ 1 1 Cl 17 _____ _____ _____ MgO Mg 12 _____ 2 2 O 8 _____ _____ _____ HF H 1 _____ 1 1 F _____ 2 , 7 _____ _____ CCl 4 C 6 _____ 4 4 Cl _____ 2 , 8 , 7 _____ _____

Electronic configuration is the distribution of electrons in different shells of an atom. Similarly, valency is equal to the number of electrons lost, gained or shared during the chemical reaction. Therefore, the given table can be completed as, Compounds Component elements Atomic number Electronic configuration Number of electrons transferred or shared or accepted Valency NaCl Na 11 2 , 8 , 1 1 1 Cl 17 2 , 8 , 7 1 1 MgO Mg 12 2 , 8 , 2 2 2 O 8 2 , 6 2 2 HF H 1 1 1 1 F 9 2 , 7 1 1 CCl 4 C 6 2 , 4 4 4 Cl 17 2 , 8 , 7 1 1

HARD

9th Kerala Board

IMPORTANT

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Examples of some covalent compounds are given draw the chemical bonds of the compounds by using electron dot diagram.

${CH}_{4}, HF, H_{2} O$

Important Questions on Chemical Bonding

HARD

9th Kerala Board

IMPORTANT

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

Some compounds and their nature are shown in the table. Complete the table by finding out the electron negativity difference between the constituent elements.

Compounds	Difference in electronegativity of the constituent elements	Nature of the compound
Carbon monoxide $(CO)$	$3.44 - 2.55 = 0.89$	Covalent
Sodium chloride $(NaCl)$		Ionic
Methane $({CH}_{4})$		Covalent
Magnesium chloride $({MgCl}_{2})$		Ionic
Sodium oxide $({Na}_{2} O)$		Ionic

HARD

9th Kerala Board

IMPORTANT

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

Consider the hydrogen chloride molecule

(HCl)

What is the electronegativity of hydrogen?
What is the electronegativity of chlorine?
The atomic nucleus of which of these elements has a greater tendency to attract the shared pair of electrons?

HARD

9th Kerala Board

IMPORTANT

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

During the formation of sodium chloride, the sodium atom donates one electron and this electron is accepted by the chlorine atom. What is the valency of these elements?

MEDIUM

9th Kerala Board

IMPORTANT

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

In the formation of magnesium oxide, how many electrons are donated by magnesium?

MEDIUM

9th Kerala Board

IMPORTANT

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

In the formation of magnesium oxide, how many electrons are accepted by oxygen?

HARD

9th Kerala Board

IMPORTANT

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

How is valency and electron transfer related in the case of the formation of magnesium oxide?

HARD

9th Kerala Board

IMPORTANT

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

In the formation of hydrogen chloride, how many electron pairs are shared? What will be the valency of each atom?

HARD

9th Kerala Board

IMPORTANT

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

Complete the table given below analyse the change in the electronic arrangement of elements during the formation of each compound. Find how they are related to valency.

Compounds	Component elements	Atomic number	Electronic configuration	Number of electrons transferred or shared or accepted	Valency
$NaCl$	$Na$	$11$	_____	$1$	$1$
$NaCl$	$Cl$	$17$	_____	_____	_____
$MgO$	$Mg$	$12$	_____	$2$	$2$
$MgO$	$O$	$8$	_____	_____	_____
$HF$	$H$	$1$	_____	$1$	$1$
$HF$	$F$	_____	$2, 7$	_____	_____
${CCl}_{4}$	$C$	$6$	_____	$4$	$4$
${CCl}_{4}$	$Cl$	_____	$2, 8, 7$	_____	_____

Examples of some covalent compounds are given draw the chemical bonds of the compounds by using electron dot diagram. CH4, HF, H2O

Important Questions on Chemical Bonding

Learn and Prepare for any exam you want !

Examples of some covalent compounds are given draw the chemical bonds of the compounds by using electron dot diagram.

${CH}_{4}, HF, H_{2} O$