chemistry MCQs - 9th class Chapter 03 Mcqs

1

According to the octet rule, what is the key to an atom's stability?

A

Having eight protons

B

Having eight electrons in the outermost shell

C

Having eight neutrons

D

Having a total of eight electrons

2

Which of the following is NOT a primary type of chemical bond mentioned in the text?

A

Ionic bond

B

Covalent bond

C

Hydrogen bond

D

Metallic bond

3

An ionic bond is described as a strong electrostatic attraction between what?

A

Two nuclei

B

Shared electrons and a nucleus

C

Oppositely charged ions

D

Delocalized electrons and cations

4

How is a covalent bond defined in the chapter?

A

Transfer of electrons

B

Attraction between oppositely charged ions

C

Strong electrostatic attraction between shared electrons and two nuclei

D

Sea of delocalized electrons

5

What do atoms do to lower their energy and increase stability?

A

Isolate themselves

B

Increase their kinetic energy

C

Combine with other atoms

D

Shed all their electrons

6

Which noble gas is noted for having two electrons in its outer shell, following the duplet rule?

A

Neon (Ne)

B

Argon (Ar)

C

Helium (He)

D

Krypton (Kr)

7

What does a sodium atom do to achieve a stable electronic configuration?

A

Gain seven electrons

B

Lose one electron

C

Share one electron

D

Lose two electrons

8

A chemical bond formed by the complete transference of an electron from one atom to another is called?

A

A covalent bond

B

A metallic bond

C

A coordinate covalent bond

D

An ionic bond

9

In the formation of sodium chloride (NaCl), which atom transfers an electron?

A

Chlorine

B

Both Sodium and Chlorine

C

Sodium

D

Neither atom transfers an electron

10

What is the charge on a calcium ion when it forms an ionic bond in CaCl2?

A

+1

B

+2

C

-1

D

-2

11

A covalent bond formed by the mutual sharing of two electron pairs is called a?

A

Single covalent bond

B

Triple covalent bond

C

Double covalent bond

D

Ionic covalent bond

12

How is a triple covalent bond represented?

A

A single line (-)

B

Two lines (=)

C

Three lines (≡)

D

A dotted line (...)

13

Which molecule contains a triple covalent bond?

A

Oxygen (O2)

B

Hydrogen (H2)

C

Chlorine (Cl2)

D

Nitrogen (N2)

14

In a coordinate covalent bond, the atom that donates the electron pair is called a?

A

Acceptor

B

Receiver

C

Anion

D

Donor

15

The formation of a hydronium ion (H3O+) is an example of which type of bond?

A

Ionic bond

B

Metallic bond

C

Coordinate covalent bond

D

Simple covalent bond

16

In the reaction between NH3 and BF3, which molecule acts as the donor?

A

BF3

B

NH3

C

Both

D

Neither

17

What is the nature of the binding forces in metals?

A

Ionic forces

B

Covalent forces

C

Metallic bond

D

van der Waals forces

18

A metallic bond is described as positively charged ions bound together by what?

A

Shared electron pairs

B

Transferred electrons

C

Mobile electrons

D

Lone pairs of electrons

19

The strength of a metallic bond depends on the number of mobile electrons and what other factor?

A

The number of neutrons

B

The size of the atoms

C

The number of positive charges on the ions

D

The electronegativity of the metal

20

Which property of metals is explained by the presence of freely moving electrons?

A

Brittleness

B

Good conduction of heat and electricity

C

Low density

D

Solubility in water

21

The property of metals to lose electrons and form positive ions is called?

A

Electronegativity

B

Electron affinity

C

Ionization energy

D

Electropositive character

22

Which elements are described as the most electronegative?

A

Alkali metals

B

Alkaline earth metals

C

Non-metals

D

Transition metals

23

What is the typical state of ionic compounds at room temperature?

A

Gases

B

Liquids

C

Solids

D

Plasma

24

What is the melting point of sodium chloride (NaCl)?

A

100°C

B

400°C

C

800°C

D

1200°C

25

In what state do ionic compounds conduct electricity?

A

Solid state

B

Gaseous state

C

Molten state or in solution

D

Only as a pure solid crystal

26

Covalent compounds are generally soluble in which type of solvents?

A

Polar solvents like water

B

Non-polar solvents like benzene

C

All solvents

D

Acids only

27

Forces of attraction present between the molecules of a substance are called?

A

Covalent forces

B

Ionic forces

C

Intermolecular forces

D

Nuclear forces

28

The boiling point of a liquid is higher if the intermolecular forces are?

A

Weaker

B

Stronger

C

Non-existent

D

Repulsive

29

Dipole-dipole forces exist between molecules of which type of compound?

A

Non-polar compounds

B

Polar compounds like HCl

C

Pure metals

D

Ionic salts

30

Hydrogen bonding is a special, strong case of which type of intermolecular force?

A

London dispersion forces

B

Ionic attraction

C

Metallic bonding

D

Dipole-dipole forces

31

Hydrogen bonding occurs when hydrogen is bonded to a highly electronegative atom such as?

A

Carbon

B

Sulphur

C

Oxygen

D

Silicon

32

Why does water have a relatively high boiling point?

A

Because of its low molecular weight

B

Because of weak intermolecular forces

C

Because of strong hydrogen bonding

D

Because it is a gas at room temperature

33

Ionic solids are described as being highly?

A

Malleable

B

Ductile

C

Brittle

D

Soft

34

Why is graphite used as a lubricant?

A

Because it is extremely hard

B

Because its layers can slip past each other

C

Because it is a non-metal

D

Because it conducts electricity

35

Which crystalline form of carbon is the hardest known substance?

A

Graphite

B

Diamond

C

Coal

D

Charcoal

36

Why does graphite conduct electricity?

A

Due to the presence of free ions

B

Due to its layered structure

C

Due to mobile electrons between its layers

D

Because it is a form of carbon

37

In the formation of CaCl2, how many electrons does a calcium atom lose?

A

One

B

Two

C

Three

D

It gains one electron

38

Which of the following molecules is formed by sharing four of its electrons with two oxygen atoms?

A

Water (H2O)

B

Methane (CH4)

C

Ammonia (NH3)

D

Carbon dioxide (CO2)

39

After forming a coordinate covalent bond, the difference between it and a normal covalent bond is?

A

The bond length

B

The bond energy

C

The bond polarity

D

There is no difference

40

Which metal is expected to have a stronger metallic bond, Sodium (Na) or Magnesium (Mg)?

A

Sodium (Na)

B

Magnesium (Mg)

C

They are equal

D

Cannot be determined

41

Non-metals tend to gain electrons to become negatively charged ions called?

A

Cations

B

Anions

C

Positrons

D

Protons

42

What is the primary reason for the low boiling points of covalent compounds like N2 and O2?

A

Strong covalent bonds within molecules

B

Very weak forces of attraction between molecules

C

High molecular mass

D

Presence of lone pairs

43

What happens to the ions of an ionic compound when it dissolves in water?

A

They form covalent bonds

B

They precipitate immediately

C

They become hydrated by water molecules

D

They turn into neutral atoms

44

The reaction between aqueous NaCl and AgNO3 produces a white precipitate of what compound?

A

NaNO3

B

AgCl

C

AgNa

D

Cl(NO3)

45

In the diamond structure, each carbon atom is covalently bonded to how many other carbon atoms?

A

Two

B

Three

C

Four

D

Six

46

Which element is mentioned as the most electronegative in the periodic table?

A

Oxygen

B

Chlorine

C

Fluorine

D

Nitrogen

47

How are atoms arranged in a metal, contributing to their hardness?

A

In random clusters

B

As individual, separate atoms

C

In the form of rows one above the other

D

In a gaseous state

48

What type of bond is formed when molten copper and molten zinc are mixed to form brass?

A

Ionic bond

B

Covalent bond

C

Coordinate covalent bond

D

Metallic bond

49

Which compound contains both ionic and covalent bonds?

A

MgCl2

B

PCl3

C

NH4Cl

D

CaO