English Medium कक्षा ९ - CBSE Question Bank Solutions for Science

Look at Fig. 1.3 and suggest in which of the vessels A,B, C or D the rate of evaporation will be the highest? Explain.

Comment on the following statements:

Evaporation produces cooling.

Comment on the following statements:

Rate of evaporation of an aqueous solution decreases with increase in humidity.

What is the fraction of the mass of water due to neutrons?

Express each of the following in kilograms

5.84 × 10⁻³ mg

Express each of the following in kilograms

58.34 g

Express each of the following in kilograms

0.584 g

Express each of the following in kilograms

58.34 g

Express each of the following in kilograms

5.873×10⁻²¹g

Compute the number of ions present in 5.85 g of sodium chloride

A group of atoms carrying a fixed charge on them is called ————.

Which of the following statements about Rutherford’s model of atom are correct?

(i) considered the nucleus as positively charged

(ii) established that the α–particles are four times as heavy as a hydrogen atom

(iii) can be compared to solar system

(iv) was in agreement with Thomson’s model

Why did Rutherford select a gold foil in his α–ray scattering experiment?

Rutherford’s α-particle scattering experiment led to the discovery of the ———

Enlist the conclusions drawn by Rutherford from his α-ray scattering experiment.

In what way is the Rutherford’s atomic model different from that of Thomson’s atomic model?

What were the drawbacks of Rutherford’s model of an atom?

Why do we hear the sound produced by the humming bees while the sound of vibrations of the pendulum is not heard?

We should not allow mosquitoes to breed in our surroundings because they

Vectors can be defined as