any one plz give me important question for Class 9 chemistry chapter 1 and 2
Answers
Answer:
what is main cause of radioactive radiation
Answer:
chapter 1
Explanation:
Question 1.
Is there any similarity in materials?
Answer:
Yes, all materials possess mass and occupy space.
Question 2.
When 50 g of sugar is dissolved in 100 mL of water, there is no increase in volume. What characteristic of matter is illustrated by this observation?
Answer:
This observation indicates that particles of water have spaces between them into which sugar particles fit.
Question 3.
What happens when an inflated air balloon is pricked with a pin? Name the property of the gaseous state exhibited by this observation.
Answer:
The balloon bursts and diffusion takes place.
Question 4.
Name the process which occurs when a drop of dettol is added to water.
Answer:
When dettol is added to water, diffusion takes place.
Question 5.
To which physical state of matter do the following statements apply?
(i) Incompressible, no fixed shape
(ii) Compressible, no definite volume
Answer:
(i) Liquid
(ii) Gas
Question 6.
Name the state of matter in which:
(i) Layers of particles can slip and slide over one another easily.
(ii) Particles just move around randomly because of very weak force of attraction.
Answer:
(i) Liquid state,
(ii) Gaseous state
Question 7.
Define density and give its SI unit.
Answer:
Density of a substance is defined as the mass per unit volume. Its SI unit is kgm-3