Exploration Entering the World of Secondary Science Class 9 Worksheet with Answers Science Chapter 1

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Class 9 Exploration Entering the World of Secondary Science Worksheet

Worksheet On Exploration Entering the World of Secondary Science Class 9

Exploration Entering the World of Secondary Science Worksheet Class 9

→ Exploration: A systematic and purposeful process of observing, questioning, and understanding the natural world.

→ Experiment: A planned procedure carried out to test a hypothesis or idea.

→ Measurement: The process of quantifying observations using standard units.

→ Symbols: The short representations (like m, v, F, I) used to denote physical quantities such as mass, velocity, force and electric current.

→ Equation: An equation is a compact statement about how certain things are related.

→ Model: A simplified representation of a real system used to understand complex phenomena.

→ Scientific Idea: An explanation or concept developed through observation and experimentation.

→ Air Resistance: The force exerted by air that opposes the motion of a moving object.

→ Standard Units (SI Units): Internationally accepted units used for consistent and accurate measurements.

→ Law: A regular pattern observed in nature, often expressed using words or mathematically.

→ Theory: An explanation of why certain patterns or events occur, based on evidence gathered over time.

→ Evidence: The data or information collected through observation and experiments that support a conclusion.

→ Principle: A broad scientific idea that is applied to explain or predict situations.

→ Prediction: A reasoned conclusion about future events based on scientific knowledge and evidence.

→ Chemical Reactions: The processes in which substances change into new substances with different properties. Biological

→ Principles: The basic concepts and rules that explain how living organisms function and interact. Scientific Theory: A well-tested explanation of natural phenomena based on evidence and repeated testing.

→ Pandemic: A disease outbreak that spreads across many countries or continents and affects a large number of people, for example, COVID-19.

→ Scientific Thinking: A way of thinking that involves logical reasoning, questioning, and reliance on evidence.

→ Estimation: The process of finding an approximate value when exact measurement is not necessary.

Class 9 Science Exploration Chapter 1 Worksheet

Class 9 Science Exploration Entering the World of Secondary Science Worksheet

A. Multiple-Choice Questions

Question 1.
Which statement best describes ‘Science’?
(a) Science removes all types of uncertainties.
(b) Science reduces uncertainties through evidence.
(c) Science depends only on fixed rules.
(d) Science avoids calculations and logical reasoning.

Question 2.
Standard units are important because they
(a) simplify models
(b) remove the need for experiments
(c) ensure consistency in measurements
(d) replace reasoning.

Question 3.
Which of the following is not a part of the scientific process?
(a) Observation
(b) Evidence-based reasoning
(c) Prediction based only on personal belief
(d) Measurement

Question 4.
Models are used to
(a) add more details
(b) simplify complex systems
(c) replace experiments
(d) avoid logical thinking.

Question 5.
A scientific theory is
(a) a random opinion
(b) a law
(c) a well-tested explanation
(d) a fixed unit of measurement.

Question 6.
Which of the following estimates is most reasonable for the mass of a school bag?
(a) 2 mg
(b) 5 kg
(c) 500 kg
(d) 50 tonnes

Question 7.
This question consists of an Assertion (A) and a Reason (R). Read the Assertion and Reason and choose the appropriate answer.
Assertion (A): Mathematics is essential in science.
Reason (R): Mathematics helps express relationships clearly.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.

Question 8.
This question consists of an Assertion (A) and a Reason (R). Read the Assertion and Reason and choose the appropriate answer.
Assertion (A): A scientific theory explains why certain patterns occur based on evidence gathered over time. Reason: Principles are broad ideas that help us understand and apply concepts in specific situations.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.

B. State True (T) or False (F).

Question 1.
If something cannot be measured, it cannot be studied scientifically.

Question 2.
A model with more assumptions is always less reliable.

Question 3.
Pounds and kilograms are different units of measurements.

Question 4.
Scientific reasoning involves the interpretation of evidence.

Question 5.
Scientific laws never change.

Question 6.
Mathematics can be used to model airflow and filtration efficiency in masks.

C. Fill in the blanks.

Question 1.
_______ helps express relationships between quantities.

Question 2.
Units used worldwide are called ______ units.

Question 3.
A ______ describes a regular pattern in nature.

Question 4.
A ______ explains why something happens.

Question 5.
_______ gives approximate values.

D. Assign one word to the following.

Question 1.
A systematic way of understanding the world through observation, experimentation, and reasoning.

Question 2.
The Latin word from which the symbol ‘c’ for the speed of light is derived

Question 3.
The physicist who explained how the colour of stars is connected to their temperature.

E. Match Column I with Column II.

Column I	Column II
(i) Model	(a) Describes a pattern
(ii) Scientific Law	(b) Approximate calculation to check reasonableness
(iii) Scientific Theory	(c) Quantifies observation
(iv) Measurement	(d) Explains pattern
(v) Estimation	(e) Simplified representation of a system

F. Differentiate between the following.
Question 1.
Differentiate between Law and Theory

G. Very Short Answer Type Questions

Question 1.
Is the statement “All scientific ideas are final and cannot be changed” correct?

Question 2.
In science, what is a ‘theory’?

Question 3.
What helps scientists make predictions?

H. Short Answer Type Questions

Question 1.
A student says, “Science is just a collection of facts.” Do you agree? Justify your answer.

Question 2.
How are scientific ideas tested and improved?

Question 3.
How does the use of standard units make science reliable?

I. Long Answer Type Questions

Question 1.
Describe the process of scientific exploration.

Question 2.
Explain how failure of a prediction can actually help scientific progress using a suitable example.

Wonder Way

A. Read the following paragraph and answer the following questions.
Rohan was watching a cricket match and wondered whether the ball would go for a six. His friend said, “We should consider everything — colour of the ball, grass on the field, crowd noise, and even the colour of the player’s jersey.”
Rohan disagreed and said that only a few factors really matter for predicting the motion of the ball.

Question 1.
Why does Rohan think that considering every detail is not useful for predicting the motion of the ball?

Question 2.
Identify any two important factors that should be considered while predicting the motion of the ball.

Question 3.
List any two factors that can be ignored in this situation.

B. Give reasons for the following.

Question 1.
Two scientists using the same data may arrive at different conclusions.

Question 2.
Scientific laws can change over time.

Question 3.
‘Kilogram’ is considered a standard unit across the worl(d)

Question 4.
Food does not become harmful during an eclipse.

Question 5.
Approximate reasoning is an important scientific skill.

Learn By Doing

A. A student tries to create a model to study the motion of a car. She includes every detail—engine structure, tyre friction, air resistance, driver behaviour, road texture, and even weather conditions. As a result, her model becomes too complex to analyse.

Question 1.
What mistake did the student make?

Question 2.
Why are simpler models often more useful?

Question 3.
If air resistance is ignored, does the model become completely wrong?

B. Riya usually takes 20 minutes to reach school. One day, it starts raining heavily. She predicts that she will still reach school in 20 minutes, assuming that her speed and travel conditions will remain unchange(d) However, she actually takes 35 minutes to reach school.

Question 1.
Analyse why Riya’s prediction faile(d) Which assumptions were unrealistic under rainy conditions?

Question 2.
Identify the factors that would most significantly affect her travel time in the rain.

Question 3.
Propose an improved way to predict travel time on rainy days. Explain what changes you would make and why they would increase accuracy.

Explore with Curiosity

A. Reema tries to predict how long it takes to boil water. She includes room temperature, size of vessel, colour of the vessel, brand of stove, and even the design on the vessel.

Question 1.
What problem might arise from including too many details?

Question 2.
Which one or two factors are most important here?

Question 3.
Why is it useful to ignore some details?

B. A passenger aircraft once faced an emergency landing because of a mix-up in measurement units. The flight required 22,300 kg of fuel, but the ground crew used fuel values in pounds (lb) instead of kilograms ikg). As a result, the aircraft received much less fuel than needed and had to make an emergency landing

Question 1.
What mistake was made by the ground crew?

Question 2.
Why is it important to use standard units (SI) in science and engineering?

Question 3.
What problems can arise from incorrect unit conversions in real-life situations?

Suggested Activities

A. Choose any everyday activity (such as cooking or playing a sport). List the important factors involved and identify the factors that can be ignored while making a simple model.

B. Observe any two products at home that show measurements (such as weight or volume). Record the units used and check whether they follow standard units.

C. Make a prediction about a daily task. Compare it with the actual result and explain any difference observed

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