Tuesday, 9 July 2019

.1.
CLASS -9 REVISION -LESSON -1
Name the property of gases due to which it is possible to fill CNG in cylinders for using as fuel in cars.

2.
List any two properties of particles of matter.

3.
When camphor is heated in a China dish, it changes into gas without changing into liquid. What is the name given to this change of state?

4.
Why light is not considered as a matter?

5.
On suffering from fever which will lower down your body temperature, more ice or ice cold water? Why?

6.
Ice, water and steam are three states of a substance and not different substances. Justify.

7.
Change the following celsius temperatures to kelvin scale:
(i) – 273 °C (ii) – 100 °C
(iii) – 40 °C (iv) + 30 °C

8.
State which property of gas is used in supplying oxygen cylinder to hospitals?

9.
Out of honey or ink which will diffuse faster and why?

10.
Give reasons for the following:
(a) Camphor disappears if kept in open air for a few days.
(b) Wet clothes do not dry easily on a rainy days.
(c) We sweat more on humid days.

11.
Give reasons for the following:
(a) Why does Ice float on water?
(b) Why does a gas fill completely the vessel in which it is kept?
(c) Latent heat of evaporation of two liquids A and B is 100 J/kg and 150 J/kg respectively. Which one can produce more cooling effect and why?

Rohan observed vendor making Kulfi without the fridge, he asked his friend Ravi how is it possible. Ravi explained he uses a mixture of ice and common salt for making Kulfi without a fridge.
(a) What are the values associated with Ravi?
(b) What is the temperature of mixture of ice and common salt?
(c) What is this mixture called?

Monday, 8 July 2019

Sunday, 7 July 2019

CLASS 8 DIFFERENCE BETWEEN MASS AND WEIGHT
Mass
Weight
Mass can never be zero.
Weight can be zero. As in space if no gravity acts upon an object, its weight becomes zero.
Mass is a scalar quantity. It has magnitude.
Weight is a vector quantity. It has magnitude and is directed toward the center of the Earth or other gravity well.
Mass is commonly measured in kilograms and grams.
Weight is commonly measured in Newtons.
Mass doesn’t change according to location.
Weight varies according to location.
The mass may be measured using an ordinary balance.
Weight is measured using a spring balance.
LESSON NOTES- METALS AND NON-METALS
CLASS 10 CHEMISTRY






MIND MAP CLASS 8
 FORCE AND PRESSURE