ICSE Class 10 Chemistry Assessment Test
NEP-Based Higher Order Thinking Skills (HOTS) Examination
Topics:
Chemical Bonding
Periodic Classification of Elements
Based on Latest ICSE Pattern
The ICSE Chemistry paper pattern consists of:
-
Section I: Compulsory short-answer questions covering the entire syllabus
-
Section II: Structured analytical questions with internal choices
Focus on:
Application-based questions
Assertion-reasoning
Diagram/data interpretation
Logical chemical analysis
-
Conceptual understanding rather than rote memorization (ICSE Portal)
ICSE CLASS 10 CHEMISTRY
NEP-Based HOTS Assessment Test
Topics: Chemical Bonding & Periodic Classification
Time: 1 Hour 30 Minutes
Marks: 40
General Instructions
Answer all questions from Section A.
Answer any FOUR questions from Section B.
The intended marks for questions are given in brackets [ ].
-
Logical reasoning and proper chemical explanation will carry marks.
Use diagrams/electron dot structures wherever required.
SECTION A (Compulsory)
[20 Marks]
Question 1
(a)
Arrange the following in increasing order of atomic size:
Na, Mg, Al, Si
Explain the reason behind the trend. [2]
(b)
Why does sodium lose an electron easily whereas chlorine tends to gain one
electron?
Explain using electronic configuration and periodic trends. [2]
(c)
An element X has atomic number 12 and element Y has atomic number 17.
Write the electronic configurations of X and Y.
Predict the type of bond formed between them.
Name the compound formed. [3]
(d)
Why do electrovalent compounds generally conduct electricity only in molten or aqueous state but not in solid state? [2]
(e)
State one reason each:
Covalent compounds generally have low melting points.
Noble gases are chemically inert. [2]
(f)
An unknown element belongs to Group 17 and Period 3 of the modern periodic table.
Identify the element.
State whether it is metallic or non-metallic.
Mention one important property of this group. [2]
(g)
Draw the electron dot structure of:
Methane (CH₄)
Carbon dioxide (CO₂) [3]
(h)
Assertion (A): Ionic compounds generally have high melting points.
Reason
(R): Strong electrostatic forces exist between oppositely charged ions.
Choose:
Both A and R are true and R is the correct explanation.
Both A and R are true but R is not the correct explanation.
A is true but R is false.
A is false but R is true. [2]
(i)
A student says:
“Elements in the same period have similar chemical properties.”
Is the statement correct? Justify your answer using electronic configuration. [2]
SECTION B
Answer any FOUR questions
[5 × 4 = 20 Marks]
Question 2
Case-Based Analytical Question
Elements A, B, and C have atomic numbers 11, 12, and 17 respectively.
Write their electronic configurations.
Identify the most metallic element.
Which pair will form an ionic compound most easily? Why?
Which element has the highest electronegativity?
-
Predict the formula of the compound formed between A and C. [5]
Question 3
Higher Order Reasoning
A scientist discovered two compounds:
Compound P conducts electricity in molten state.
Compound Q does not conduct electricity in any state.
Answer the following:
Identify which compound is ionic and which is covalent.
Explain the reason for their conductivity behavior.
Which compound is likely to have a lower boiling point? Why?
Give one example each of P and Q. [5]
Question 4
Diagram & Concept Application
Study the partial periodic table below:
| Group 1 | Group 17 |
|---|---|
| Li | F |
| Na | Cl |
| K | Br |
Answer the following:
Which element has the largest atomic radius?
Which element is most reactive among halogens?
Why does reactivity increase down Group 1?
Why does reactivity decrease down Group 17?
-
Name one compound formed between Na and Cl and state its bond type. [5]
Question 5
HOTS – Real Life Chemistry
Common salt (NaCl) is essential in daily life.
-
Explain how sodium and chlorine atoms achieve stable configuration during bond formation.
Why is sodium chloride hard and brittle?
Why does NaCl dissolve easily in water?
Why is NaCl not considered a molecule? [5]
Question 6
Critical Thinking Question
A student observed:
Diamond does not conduct electricity.
Graphite conducts electricity though both are made of carbon.
Explain:
Why diamond is hard.
Why graphite conducts electricity.
Which allotrope has layered structure?
Which allotrope is used in electrodes and why? [5]
Question 7
Competency-Based Mixed Question
Define electronegativity.
State the trend of electronegativity across a period.
Why does fluorine have the highest electronegativity?
Why do noble gases usually not form compounds?
-
Differentiate between ionic and covalent bond using one point each. [5]
Marking Scheme (Teacher Reference)
| Skill Assessed | Weightage |
|---|---|
| Conceptual Understanding | 10 |
| Logical Reasoning | 10 |
| Application & Analysis | 10 |
| Diagrammatic Representation | 5 |
| Scientific Communication | 5 |
NEP-Based Features Included
Competency-based questions
Assertion–Reasoning
Case-study questions
Real-life application
Analytical reasoning
Concept integration
HOTS-oriented structure
Reduced rote memorization focus
This paper follows the ICSE examination structure and modern competency-based NEP assessment style emphasizing conceptual clarity and analytical thinking. (ICSE Portal)
ICSE Class 10 Chemistry Assessment Test
Answer Key with Explanations & Reasons
SECTION A
Question 1
(a)
Arrange in increasing order of atomic size:
Na, Mg, Al, Si
Answer:
Si < Al < Mg < Na
Reason:
Across a period from left to right, atomic size decreases because nuclear charge increases while electrons are added to the same shell. Greater attraction pulls electrons closer to the nucleus.
(b)
Answer:
-
Sodium (2,8,1) loses one electron easily because by losing one electron it attains stable noble gas configuration (Neon).
-
Chlorine (2,8,7) gains one electron because it requires one electron to complete its octet.
Reason:
Atoms tend to achieve stable electronic configuration with 8 valence electrons.
(c)
Answer:
Electronic configurations:
X (12): 2,8,2
Y (17): 2,8,7
-
Type of bond:
Ionic (Electrovalent) bond -
Compound formed:
Magnesium chloride (MgCl₂)
Reason:
Magnesium loses 2 electrons while chlorine gains 1 electron each.
(d)
Answer:
Electrovalent compounds conduct electricity only in molten or aqueous state because ions become free to move.
Reason:
In solid state, ions are fixed in crystal lattice and cannot carry charge.
(e)
Answer:
-
Covalent compounds generally have low melting points because intermolecular forces are weak.
-
Noble gases are chemically inert because their outermost shell is completely filled.
(f)
Answer:
Element = Chlorine (Cl)
Non-metal
Group 17 elements are highly reactive and form salts.
Reason:
Chlorine belongs to Period 3 and Group 17.
(g)
Answer:
Methane (CH₄)
Carbon shares four pairs of electrons with four hydrogen atoms.
Carbon dioxide (CO₂)
Carbon forms double covalent bonds with two oxygen atoms.
Reason:
Atoms share electrons to complete octet/duplet configuration.
(h)
Answer:
Both A and R are true and R is the correct explanation.
Reason:
Strong electrostatic force between ions requires large energy to break.
(i)
Answer:
The statement is incorrect.
Reason:
Elements in the same group have similar chemical properties because they
possess same number of valence electrons.
Elements in the same period
have different valence electrons.
SECTION B
Question 2
1. Electronic configurations
A (11) → 2,8,1
B (12) → 2,8,2
C (17) → 2,8,7
2. Most metallic element
A (Sodium)
Reason:
It loses electron most easily.
3. Pair forming ionic compound most easily
A and C
Reason:
A loses 1 electron and C gains 1 electron.
4. Highest electronegativity
C (Chlorine)
Reason:
Non-metals strongly attract electrons.
5. Formula of compound
NaCl
Question 3
1. Identify compounds
P → Ionic compound
Q → Covalent compound
2. Conductivity behavior
Ionic compounds conduct in molten state due to free ions.
Covalent
compounds lack free ions/electrons.
3. Lower boiling point
Q (Covalent compound)
Reason:
Weak intermolecular forces require less energy.
4. Examples
P → NaCl
Q → CO₂ or CH₄
Question 4
1. Largest atomic radius
K (Potassium)
Reason:
Atomic size increases down the group due to addition of shells.
2. Most reactive halogen
F (Fluorine)
Reason:
It gains electron most easily due to small atomic size.
3. Reactivity increases down Group 1
Reason:
Valence electron becomes farther from nucleus and is lost more easily.
4. Reactivity decreases down Group 17
Reason:
Ability to gain electron decreases due to larger atomic size.
5. Compound formed
Sodium chloride (NaCl)
Bond type:
Ionic bond
Question 5
1. Stable configuration in NaCl
-
Sodium loses one electron:
Na → Na⁺ + e⁻ -
Chlorine gains one electron:
Cl + e⁻ → Cl⁻
Both attain octet configuration.
2. Why NaCl is hard and brittle
Reason:
Strong ionic forces hold ions tightly in crystal lattice.
3. Why NaCl dissolves in water
Reason:
Water molecules surround and separate ions.
4. Why NaCl is not considered a molecule
Reason:
It exists as ionic crystal lattice, not discrete molecules.
Question 6
1. Why diamond is hard
Reason:
Each carbon atom forms four strong covalent bonds in 3D structure.
2. Why graphite conducts electricity
Reason:
One electron per carbon atom remains free and mobile.
3. Allotrope with layered structure
Graphite
4. Used in electrodes
Graphite
Reason:
It conducts electricity.
Question 7
1. Define electronegativity
Ability of an atom to attract shared pair of electrons toward itself.
2. Trend across a period
Electronegativity increases from left to right.
Reason:
Nuclear charge increases.
3. Why fluorine has highest electronegativity
Reason:
Small atomic size and high nuclear charge.
4. Why noble gases usually do not form compounds
Reason:
They already possess stable electronic configuration.
5. Difference between ionic and covalent bond
| Ionic Bond | Covalent Bond |
|---|---|
| Formed by transfer of electrons | Formed by sharing of electrons |
ICSE Class 10 Chemistry
ADVANCED NEP-BASED HOTS WORKSHEET
Topics:
Chemical Bonding
Periodic Classification of Elements
Level: Advanced ICSE + Olympiad Style Reasoning
Total Marks: 60
Time: 2 Hours
Instructions
This worksheet is competency-based and logic-intensive.
Write complete chemical reasoning wherever necessary.
Mere answers without justification may not fetch full marks.
Draw neat electron-dot structures where required.
Use periodic trends logically instead of memorized statements.
SECTION A
Conceptual HOTS & Analytical Questions
[2 marks each]
1.
An atom X has electronic configuration 2,8,8,1 while atom Y has 2,8,7.
Without naming the elements:
Predict the formula of the compound formed.
State the type of bond.
-
Predict whether the compound will conduct electricity in solid state.
2.
Why does atomic radius decrease across a period even though electrons are being added?
Explain using nuclear charge concept.
3.
Two compounds have the following properties:
| Compound A | Compound B |
|---|---|
| Soluble in water | Insoluble in water |
| Conducts in molten state | Does not conduct |
| High melting point | Low melting point |
Identify which is ionic and which is covalent with reasons.
4.
Why do metals generally form cations while non-metals form anions?
Relate your answer to:
Ionization energy
Electron affinity
5.
A student says:
“All compounds containing bonds are molecules.”
Is the statement scientifically correct? Justify with examples.
6.
Why does fluorine form only one covalent bond whereas carbon forms four?
Explain using valency and electronic configuration.
7.
Among Na, Mg, Al and Si:
Which has highest metallic character?
Which has smallest atomic size?
Which has highest ionization energy?
Give reasons.
8.
Why are ionic compounds brittle even though they possess strong forces of attraction?
9.
An element belongs to Group 2 and Period 3.
Identify the element.
State its valency.
Predict the formula of its chloride.
10.
Why do noble gases have zero valency?
SECTION B
Assertion–Reasoning & Critical Thinking
[3 marks each]
11.
Assertion (A):
Covalent compounds are generally poor conductors of
electricity.
Reason (R):
Covalent compounds do not possess free ions.
12.
Assertion (A):
Chlorine is more reactive than bromine.
Reason (R):
Chlorine has smaller atomic size than bromine.
13.
Assertion (A):
Electronegativity increases across a period.
Reason (R):
Atomic size decreases across a period.
14.
Assertion (A):
Graphite conducts electricity.
Reason (R):
Graphite contains free electrons between layers.
15.
Assertion (A):
NaCl has high melting point.
Reason (R):
Strong electrostatic forces exist between ions.
SECTION C
Case Study Based Questions
[5 marks each]
Case Study 1
Scientist M discovered a solid compound with the following properties:
Hard crystalline solid
High melting point
Soluble in water
Conducts electricity in molten state
Questions:
Identify the type of compound.
Explain why it conducts in molten state.
Why does it have high melting point?
Predict whether it is made of molecules or ions.
Give one example.
Case Study 2
An unknown element X has:
Atomic number = 16
Questions:
Write its electronic configuration.
Identify its group and period.
State whether it is metal or non-metal.
Predict its valency.
Predict formula of compound formed with hydrogen.
Case Study 3
Element A belongs to Group 1.
Element B belongs to Group 17.
Questions:
Predict the type of bond formed.
Which element loses electron?
Which element gains electron?
Why are Group 17 elements highly reactive?
Name one real-life compound formed by such bonding.
SECTION D
Advanced Application & Multi-Concept HOTS
[6 marks each]
16.
Compare ionic and covalent compounds on the basis of:
| Property | Ionic | Covalent |
|---|---|---|
| Melting point | ? | ? |
| Conductivity | ? | ? |
| Solubility | ? | ? |
| Nature of particles | ? | ? |
| Bond formation | ? | ? |
| Physical state | ? | ? |
17.
An element X forms an oxide X₂O while another element Y forms oxide YO.
Determine valency of X and Y.
Which element is likely to belong to Group 1?
Which belongs to Group 2?
Predict whether oxides are ionic or covalent.
Explain your reasoning.
18.
Carbon forms two important allotropes: diamond and graphite.
Explain differences in:
Structure
Hardness
Electrical conductivity
Bonding
Uses
19.
Study the periodic trends and answer:
Why does metallic character decrease across a period?
Why does non-metallic character increase across a period?
Why does atomic size increase down a group?
Why do alkali metals become more reactive down the group?
Why do halogens become less reactive down the group?
Which element is most electronegative?
20.
An element X has atomic number 13 and element Y has atomic number 8.
Write electronic configurations.
Determine valencies.
Predict type of bond formed.
Explain electron transfer/sharing process.
Predict formula of compound formed.
-
State whether compound will conduct electricity in molten state.
SECTION E
Olympiad-Level HOTS
[5 marks each]
21.
Why is magnesium more reactive than aluminum even though both are metals?
(Hint: Relate to atomic size and ionization energy.)
22.
A compound AB₂ is formed between two elements.
Element A loses two electrons while each B gains one electron.
Identify likely groups of A and B.
Predict nature of bond.
State one physical property of compound.
Explain formation of AB₂.
23.
Why does water (H₂O) have covalent bonding but still dissolve ionic compounds effectively?
24.
A student observed:
Sugar dissolves in water but does not conduct electricity.
Salt dissolves in water and conducts electricity.
Explain scientifically.
25.
Why is periodic classification considered one of the greatest achievements in chemistry?
Include:
Prediction of properties
Arrangement of elements
Scientific organization
Chemical behavior trends
ICSE Class 10 Mathematics
NEP-Based HOTS Worksheet
Topic: Coordinate Geometry – Section Formula
(Point Dividing the Line Joining Two Points)
Worksheet Objectives
This worksheet is designed to develop:
Logical reasoning
Analytical thinking
Geometrical visualization
Algebraic application
Multi-step problem solving
Real-life mathematical interpretation
Important Formula
For a point ( P(x,y) ) dividing the line segment joining
( A(x_1,y_1) )
and ( B(x_2,y_2) ) internally in the ratio ( m:n ),
the coordinates of P are:
P\left(\frac{mx_2+nx_1}{m+n},\frac{my_2+ny_1}{m+n}\right)
For external division:
P\left(\frac{mx_2-nx_1}{m-n},\frac{my_2-ny_1}{m-n}\right)
SECTION A
Conceptual HOTS
[2 Marks Each]
1.
A point divides the line joining A(2,4) and B(8,10) internally in the ratio 1:2.
Without directly applying the formula:
Predict whether the point lies closer to A or B.
Explain your reasoning.
2.
Why does the section formula resemble a weighted average of coordinates?
Explain conceptually.
3.
A student calculated the midpoint using section formula with ratio 2:2.
Will the answer be correct? Justify mathematically.
4.
If a point divides a line externally, why can the coordinates obtained sometimes lie outside the segment?
Explain geometrically.
5.
Can the section formula be applied vertically and horizontally oriented lines?
Explain with reasoning.
6.
Two points are A(–3,5) and B(7,5).
Without calculation:
Predict the y-coordinate of every point on the line.
Explain why.
7.
Why is the midpoint considered a special case of section formula?
8.
A point P divides AB internally in ratio 5:1.
Which endpoint is P nearer to? Explain logically.
9.
Can a section point have coordinates larger than both endpoints during external division?
Explain with example-based reasoning.
10.
Why is coordinate geometry considered a bridge between algebra and geometry?
SECTION B
Application & Analytical Questions
[3 Marks Each]
11.
Find the coordinates of the point dividing the line joining A(2,3) and B(8,15) internally in the ratio 1:2.
12.
Find the coordinates of the midpoint of the line segment joining:
A(–6,7)
and B(10,–5)
Using section formula.
13.
A point P divides the line joining A(4,–2) and B(10,16) internally in ratio 3:1.
Find coordinates of P.
Verify whether P lies nearer to A or B.
14.
Find the point dividing the line segment joining:
A(–2,4) and
B(6,–8)
externally in the ratio 2:1.
15.
A point divides the line joining A(1,5) and B(7,17) in ratio k:1 and its coordinates are (4,11).
Find k.
SECTION C
Higher Order Thinking Skills (HOTS)
[5 Marks Each]
16.
The midpoint of the line joining A(x,4) and B(8,10) is (5,7).
Find:
Value of x
Length reasoning of midpoint concept
17.
A point P divides the line joining A(2,6) and B(14,18) internally.
If x-coordinate of P is 8, find:
Ratio in which P divides AB
y-coordinate of P
18.
Determine whether the following points are collinear:
A(1,2), B(4,8), C(7,14)
Using section formula logic.
19.
A point P divides the line joining A(–4,6) and B(8,–3) externally in ratio 2:1.
Find coordinates of P.
-
Explain geometrically why external division differs from internal division.
20.
The midpoint of a line segment is M(3,5).
One endpoint is A(–1,7).
Find the other endpoint B.
SECTION D
Competency-Based Case Study Questions
[5 Marks Each]
Case Study 1
A drone travels from point A(2,4) to B(14,16).
A checkpoint P divides
the route internally in the ratio 1:2.
Questions:
Find coordinates of checkpoint P.
Is P nearer to A or B?
Explain why section formula is useful in navigation systems.
What happens to coordinates if ratio becomes 1:1?
Name the mathematical concept obtained in that case.
Case Study 2
A road connects two villages located at:
A(–6,2) and B(10,14).
A water tank is to be constructed exactly midway.
Questions:
Find coordinates of water tank.
Why is midpoint practically useful in planning?
-
If another tank divides road in ratio 3:1, which village is it nearer to?
Explain using section formula logic.
State one real-life use of coordinate geometry.
SECTION E
Olympiad-Level HOTS
[6 Marks Each]
21.
A point P divides the line joining A(2,3) and B(12,18) in ratio m:n.
If coordinates of P are (7,10.5), determine m:n.
22.
Find coordinates of the point which divides the line joining:
A(–5,7)
and B(15,–13)
internally in such a way that:
x-coordinate is double the y-coordinate.
23.
A point divides the line joining A(–3,4) and B(9,16) externally in ratio k:2.
If x-coordinate of point is 21, find:
k
y-coordinate
24.
Using section formula, prove that the midpoint of the hypotenuse of a right triangle is equidistant from all three vertices.
25.
A line segment joining A(–2,5) and B(8,–15) is divided into four equal parts.
Find coordinates of all division points.
Challenge Problem
26.
A treasure map marks two locations:
A(–10,6) and B(14,–18).
The treasure lies at a point dividing AB internally such that:
Distance from A : Distance from B = 3 : 5
Find the treasure coordinates.
Then explain:
Why the point lies nearer to A or B.
How ratio affects position geometrically.