Chemical Bonding
Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.
Octet Rule-advanced
SubtopicOctet Rule-advanced under Chemical Bonding for Grade 9 CBSE.
Preview questions (no answers)
- 1.
What happens to the energy of a system when a chemical bond is formed following the octet rule?
A.Increases
B.Decreases
C.Remains same
D.Becomes zero
- 2.
In , Lithium () loses one electron. What rule does the Lithium ion follow?
A.Octet Rule
B.Duet Rule
C.Triad Rule
D.None
- 3.
The octet rule is based on the chemical stability of:
A.Hydrogen
B.Metals
C.Noble Gases
D.Halogens
- 4.
How many electrons does an Oxygen atom have in its valence shell?
A.2
B.4
C.6
D.8
- 5.
In the formation of the ionic compound Calcium Phosphide (), Calcium () and Phosphorus () react to achieve stable electronic configurations. According to the octet rule, what is the total number of electrons transferred from the Calcium atoms to the Phosphorus atoms to satisfy the octet of all ions in a single formula unit?
A.2
B.3
C.5
D.6
- 6.
Which of the following pairs of elements will form an ionic bond based on the octet rule?
A.Carbon and Oxygen
B.Hydrogen and Chlorine
C.Sodium and Fluorine
D.Nitrogen and Hydrogen
- 7.
Which type of bonding occurs when atoms with high electronegativity share electrons to complete their octets?
A.Ionic
B.Metallic
C.Covalent
D.Hydrogen bonding
- 8.
Which molecule does NOT exhibit resonance among the following?
A.B.C.D. - 9.
The total number of electrons shared in a molecule of Ethyne () to satisfy the octet of Carbon atoms is:
A.6
B.8
C.10
D.12
- 10.
Which of the following will have the highest bond dissociation energy?
A.B.C.D.
Download the worksheet for Chemical Bonding - Octet Rule-advanced to practice offline. It includes additional chapter-level practice questions.
Lewis Approach-advanced
SubtopicLewis Approach-advanced under Chemical Bonding for Grade 9 CBSE.
Preview questions (no answers)
- 1.
Which molecule has only single bonds and no lone pairs on the central atom?
A.B.C.D. - 2.
If an element is in Group 15 of the Periodic Table, how many dots will it have in its Lewis dot symbol?
A.3
B.5
C.8
D.15
- 3.
How many electrons are in the outermost shell of the ion?
A.1
B.2
C.3
D.8
- 4.
Which of the following elements has the highest number of dots in its Lewis symbol?
A.Carbon
B.Oxygen
C.Fluorine
D.Neon
- 5.
According to the Lewis theory, the 'kernel' of an atom consists of:
A.Only the nucleus
B.Valence electrons and nucleus
C.Inner shell electrons and nucleus
D.Only electrons
- 6.
Which of the following molecules has a coordinate covalent bond?
A.B.C.D. - 7.
In the Lewis structure of , the Carbon atom is surrounded by how many valence electrons?
A.4
B.6
C.8
D.10
- 8.
How many resonance structures are usually drawn for the Nitrate ion () to represent the delocalization of electrons?
A.B.C.D. - 9.
In the Lewis structure of , how many electrons surround the central Iodine atom?
A.B.C.D. - 10.
Which of the following Lewis structures represents a 'free radical'?
A.B.C.D.
Download the worksheet for Chemical Bonding - Lewis Approach-advanced to practice offline. It includes additional chapter-level practice questions.
Exceptions of Octet Rule-advanced
SubtopicExceptions of Octet Rule-advanced under Chemical Bonding for Grade 9 CBSE.
Preview questions (no answers)
- 1.
Which of the following central atoms has 10 electrons in its valence shell?
A.in
B.in
C.in
D.in
- 2.
In , which atom has the unpaired (odd) electron?
A.Nitrogen
B.Oxygen
C.Both share it
D.Hydrogen
- 3.
Molecules like and are often called:
A.Hypovalent
B.Hypervalent
C.Ionic compounds
D.Metallic bonds
- 4.
Which noble gas does NOT have 8 electrons in its valence shell?
A.Neon
B.Helium
C.Argon
D.Xenon
- 5.
What is the primary limitation of the Lewis octet rule?
A.It cannot explain the shape of molecules
B.It doesn't apply to all atoms
C.It doesn't explain the relative stability of molecules
D.All of the above
- 6.
In the molecule , aluminum acts as a:
A.Lewis Acid
B.Lewis Base
C.Neutral molecule
D.Ionic crystal
- 7.
Which gas is known to form compounds despite having a complete octet initially?
A.Helium
B.Neon
C.Xenon
D.Argon
- 8.
Which of the following is the most significant limitation of the Lewis octet theory?
A.It cannot explain the geometry of molecules
B.It cannot explain the relative stability of molecules
C.It fails for heavy elements
D.All of the above
- 9.
Which molecule has an odd electron and is paramagnetic?
A.B.C.D. - 10.
In the molecule , phosphorus follows the octet rule. In , it does not. What is the difference in the number of valence electrons between the two?
A.2
B.4
C.1
D.3
Download the worksheet for Chemical Bonding - Exceptions of Octet Rule-advanced to practice offline. It includes additional chapter-level practice questions.
Metallic Bonding-advanced
SubtopicMetallic Bonding-advanced under Chemical Bonding for Grade 9 CBSE.
Preview questions (no answers)
- 1.
Metallic bonds are found in which of the following?
A.Diamond
B.Solid Sodium Chloride
C.Copper pipe
D.Sugar crystals
- 2.
Gold is used in jewelry partly because of its 'lustre'. This is a result of:
A.Its high cost
B.Metallic bonding and mobile electrons
C.Its density
D.Its radioactivity
- 3.
Sodium is a soft metal because:
A.It has many valence electrons
B.It has only one delocalized electron per atom
C.It has no metallic bonds
D.It is a non-metal
- 4.
Which type of bonding allows for the 'sliding of layers'?
A.Covalent
B.Ionic
C.Metallic
D.Network Covalent
- 5.
The strength of a metallic bond is determined by the electrostatic attraction between the positive kernels and the delocalized 'sea' of electrons. If Metal A and Metal B both have the same number of valence electrons, but Metal A has a smaller ionic radius than Metal B, what can be concluded about their metallic bonds?
A.Metal B has a stronger metallic bond because the larger size allows for more mobile electrons.
B.Metal A has a stronger metallic bond because the delocalized electrons are closer to the positive nuclei.
C.Both metals have the same bond strength because they have the same number of valence electrons.
D.Metal A has a weaker metallic bond because smaller kernels have a lower total number of protons.
- 6.
The strength of a metallic bond depends on:
A.The number of protons in the nucleus only
B.The number of delocalized electrons and the charge/size of the kernels
C.The total number of neutrons in the atom
D.The color of the metal
- 7.
Metallic bonding is found in:
A.Sodium chloride crystal
B.Diamond
C.A piece of Copper wire
D.Water molecules
- 8.
How does the size of the metal cations influence the density of the metal?
A.Smaller cations allow for closer packing, which generally increases density.
B.Larger cations always make the metal denser.
C.Cation size has no effect on density.
D.Density is only determined by the number of neutrons.
- 9.
What characterizes a 'metallic glass'?
A.It is a metal that is transparent like window glass.
B.It is a metallic alloy with an amorphous (non-crystalline) atomic structure.
C.It is a mixture of sand and iron.
D.It is a metal that shatters when heated.
- 10.
Why is Lead () much less conductive than Copper ()?
A.Lead has no valence electrons.
B.Lead has a much larger atomic radius and its outer electrons are more tightly held/less mobile due to the 'inert pair effect'.
C.Copper is a liquid.
D.Lead's cations are larger than Copper's.
Download the worksheet for Chemical Bonding - Metallic Bonding-advanced to practice offline. It includes additional chapter-level practice questions.
Electron Sea Model-advanced
SubtopicElectron Sea Model-advanced under Chemical Bonding for Grade 9 CBSE.
Preview questions (no answers)
- 1.
What is the charge of the 'sea' in a neutral piece of metal?
A.Positive
B.Negative
C.Neutral overall (balanced by cations)
D.Infinite
- 2.
The concept that 'electrons belong to the whole crystal rather than individual atoms' is the essence of:
A.Covalent bonding
B.Ionic bonding
C.Metallic bonding (Electron Sea Model)
D.Hydrogen bonding
- 3.
Which subatomic particle is the 'mobile' part of the electron sea model?
A.Electron
B.Proton
C.Neutron
D.Positron
- 4.
The strength of the metallic bond depends on the ratio of ____ to the size of the ion.
A.Neutrons
B.Charge
C.Protons
D.Mass
- 5.
In the electron sea model, the kernels are held in place by their attraction to ______.
A.Each other
B.The delocalized electrons
C.The air
D.The container
- 6.
The property of 'alloys' where different sized atoms are mixed can be explained by the electron sea model because:
A.The sea of electrons can still hold different types of kernels together
B.Alloys don't have electrons
C.Only atoms of the same size can share an electron sea
D.The electrons must be of different sizes too
- 7.
Which of the following is true about the speed of electrons in the sea model during electrical conduction?
A.They move at the speed of light
B.Individual electrons have a slow drift velocity, but the signal travels fast
C.They move faster than the speed of sound but slower than light
D.They don't move at all; they just vibrate
- 8.
What constitutes a 'hole' in advanced extensions of the electron sea model?
A.A physical gap in the metal where an atom is missing.
B.The absence of an electron in a normally filled energy level, behaving like a positive charge carrier.
C.A place where the electron sea has evaporated.
D.A tunnel through the kernel.
- 9.
In the electron sea model, the 'Kinetic Energy' of the delocalized electrons:
A.Is zero at room temperature.
B.Is significantly higher than the thermal energy due to quantum confinement (Fermi energy).
C.Is provided entirely by the battery in a circuit.
D.Decreases as the metal is heated.
- 10.
Why is the bond in Magnesium stronger than in Sodium?
A.Sodium has more protons.
B.Magnesium has a higher 'valency-to-size' ratio, creating a higher charge density in the electron sea.
C.Sodium's electrons are more delocalized.
D.Magnesium is a gas at room temperature.
Download the worksheet for Chemical Bonding - Electron Sea Model-advanced to practice offline. It includes additional chapter-level practice questions.