June 13, 2024

“Learning is never done without errors.”

# 9th Term-2 Science Sample Paper

## SAMPLE – PAPER

### Term-II Examination (2021-22)

Class – 9th

Subject – Science

Time – 2 Hrs.                                                                                       M.M. – 40

### General Instructions:

1. All questions are compulsory.
2. The question paper has three sections and 15 questions.
• Section–A has 7 questions of 2 marks each; Section–B has 6 questions of 3 marks each; and Section–C has 2 case-based questions of 4 marks each.
1. Internal choices have been provided in some questions. A student has to attempt only one of the alternatives in such questions.

## Section – A

1 Write down the formulae of
(i) Sodium oxide(ii) Aluminium chloride(iii) Sodium sulphide(iv) Magnesium hydroxide
2
2 Which has more number of atoms, 100 grams of sodium or 100 grams of iron (given atomic mass of Na = 23 u, Fe = 56 u)?

OR

Convert into mole.

(a) 20 g of water
(b) 22 g of Carbon dioxide.

2
3 On the basis of Thomson’s model of an atom, explain how the atom is neutral as a whole.

2
4 Why does an object float or sink when placed on the surface of water?

OR

You find your mass to be 42 kg on a weighing machine. Is your mass more or less than 42 kg?

2
5 The volume of 50 g of a substance is 20 cm3. If the density of water is 1 gem 3, will the substance float or sink?

2
6 Soni says that the acceleration in an object could be zero even when several forces are acting on it. Do you agree with her? Why?

2
7 What are infectious diseases?

2

## Section – B

1 Calculate the molecular masses of Cl2, C02, CH4, C2H2, NH3, CH3OH.

OR

Calculate the formula unit masses of ZnO, Na2O, K2C03, given atomic masses of Zn = 65 u, Na = 23 u, K = 39 u, C = 12 u, and O = 16 u.

3
2 What is the mass of
(a) 1 mole of nitrogen atoms?(b) 4 moles of aluminium atoms (Atomic mass of aluminium = 27)?
(c) 10 moles of sodium sulphite (Na2S03)?
3
3 How will you find the valency of chlorine, sulphur and magnesium?

3
4 Reeta was wearing a high heel shoe for a beach party, her friend told her to wear flat shoes as she will be tired soon with high heels and will not feel comfortable,
(a) Why would one feel tired with high heel shoes on beach?(b) Give the unit of pressure.(c) What value of Reeta’s friend is seen in the above act?
3
5 Find the energy in kWh consumed in 10 hours by four devices of power 500 W each.

3
6  Define vaccine and name two vaccines.

OR

How many times did you fall ill in the last one year? What were the illnesses?
(a) Think of one change you could make in your habits in order to avoid any of/ most of the above illnesses.

(b) Think of one change you would wish for in your surroundings in order to avoid any of/most of the above illness.

3

## Section – C

1 Explain with examples:
(i) Atomic number(ii) Mass number,(iii) Isotopes and(iv) Isobars.

OR

The average atomic mass of a sample of an element X is 16.2 u. What are the percentages of isotopes 168X and 188X in the sample?

4
2 What precautions can you take in your school to reduce the incidence of infectious diseases?

OR

What is AIDS? How does a person get affected with HIV?

4

CBSE Examination 2021-22