Exercise
NCERT Science Solutions for Exercise
Simple step-by-step solutions to Exercise questions of Atoms and Molecules from Science Textbook of Competency Based Questions for Class IX. Also get 3D topic explainers, cheat sheets, and unlimited doubts solving on EMBIBE.
Questions from Exercise with Hints & Solutions
The particles are very close together and held in fixed places by strong bonds, so the particles cannot move around. This causes distinct boundaries for a solid.
The rate of diffusion of a gas at atmospheric pressure will be _____ times that at atmospheric pressure, temperature remaining constant.
Look at the pictures and answer the question below.
Which process is associated with these pictures?
Read the passage and answer the following question-
Latent Heat
The term latent means hidden. The latent heat of a substance is the amount of heat absorbed by a unit mass of the substance to change its state without a change of temperature. Its SI unit is Joules per kilogram. Latent heat is of two types:
1. Latent heat of fusion.
2. Latent heat of vaporization.
The Latent heat of fusion of a solid is the quantity of heat in Joules required to convert 1 KG of solid (at its melting point) to liquid, with no change in temperature.
The Latent heat of vaporization of a liquid is the quantity of heat in Joules required to convert 1 KG of the liquid (at its boiling point) to gas with no change in temperature.
Specific heat
It is the amount of heat that is required to raise the temperature of a unit mass of the substance by 1 °C. The symbol is C or S. The specific heat varies slightly with temperature. This is due to varies slightly with the change which occurs in the structure of molecules in a substance with change in temperature. The unit of specific heat is Joules per kilogram per degree Celsius
Identify which conversion will require a larger amount of energy?
(i) 1kg of ice at 0 °C to 1kg of water at 0 °C.
(ii) 1kg of water at 100 °C to 1kg of steam at 100 °C
A student heats a beaker containing ice and water. He measures the temperature of the contents of the beaker as a function of time. Which of the following would correctly represent the result? Give justification for your choice.
Which among the following contains atoms of’ oxygen?
The atomic mass of four elements are given below:
| Carbon | Helium | Calcium | Nitrogen | |
| Atomic Mass |
Molar mass is the mass of mole of an element or a compound. Which element has the highest molar mass?
Which of the following statement is incorrect?
