Matter in Our Surroundings- Blog 1

SCIENCE IX

CHEMISTRY

Chapter 1: MATTER IN OUR SURROUNDINGS-I

"There exists a passion of comprehension, without this passion there would be neither mathematics nor natural sciences."     -Albert Einstein

Good Morning!! Learners,

Welcome to the first blog for this chapter. 

At the end of this topic, the student will be able to-

•   define matter.
•   describe the composition of matter.
•   tabulate the properties of particles of matter.

Important Instructions

A few guidelines to go through the blog.

1.     the text in red is to be written in your separate Chemistry Notebook

2.     the text in violet is to viewed by clicking on it.

INTRODUCTION

 A pencil, a pen, a table, the food we eat, the clothes we wear, the walls of our houses – everything around is made up of matter.

But what is matter? 

Matter is anything that occupies space has mass. (They have both mass and volume.)

In other words “Matter is used to cover all the substances and the materials from which the universe is made."

Let us elaborate on this by watching the following video.

https://www.youtube.com/watchreload=9&v=D9h8HqjH_Oo

(View by clicking on it)

Were you able to access the video? If yes, please answer why anger is not considered as matter?

(Hint: what does matter possess and anger does not?)

The ancient Indian and Greek philosophers believed that Matter is classified into five basic elements (the Indians called these "Panch Tatva" ) ---air, water, earth, fire and sky.

For a long time, two schools of thoughts prevailed regarding the nature of matter.

• Matter can be continuous like a block of wood.
• Matter can be particulate, made up of particles like sand.

Physical Nature of Matter

1.1.1 Matter is made up of particles

Refer to Activity 1.1 Page1 NCERT.
Conclusion: This experiment shows that matter is made up of particles. 

1.1.2 How small are these particles of matter?

Refer to Activity 1.2 Page 1-2 NCERT

Conclusion: The matter is matter is made up tiny particles which keepon divding themselves into smaller and smaller particles.

https://www.youtube.com/watch?v=ulBpJTkC17Y (watch the video till 2:58min)

After watching the video you will be able to imagine how small these particles of matter are. The particles of matter are very small-they are small beyond our imagination.

CHARACTERISTICS OF PARTICLES OF MATTER

1.2.1 Particles of matter have space between them

Read Page 2 NCERT

Conclusion: Particles of one type of matter get into the spaces between particles of the other. This shows that there is enough space between particles of matter.

1.2.2 Particles of matter are continuously moving

Refer Acitivity 1.3, 1.4, 1.5 Page 2 NCERT

Conclusion: Particles of matter are continuously moving, that is they posses kinetic energy. As the temperature rises, particles move faster. So with the increase in temperature the kinetic energy of the particles also increases.

Therefore, the characteristic of particles of matter are-

• Particles of matter are very very small in size.
• Particles of matter have space between them.
• Particles of matter are continuously moving.
• Particles of matter attract each other.

https://www.youtube.com/watch?v=OjElFVfHdWs

Illustration:  What happens to the sugar when it dissolves in water? Where does the sugar go? What information do you get about the nature of matter from the dissolution of sugar in water?

Solution: (a) When sugar dissolves in water, its tiny particles break off from the solid sugar crystals.

(b) the sugar particles go into the spaces between the particles of water and mix with them (to form sugar solution). 

(c) The dissolution of sugar in water tells us that:

i) The matter (here sugar and water) is made up of small particles.

ii) The particles of matter (here water) have spaces between them.

DIFFUSION

“The mixing and spreading out of a substance with another substance due to the movement or motion of its particles is called diffusion.”

The diffusion of one substance into another substance goes on until a uniform mixture is formed. This is the process where the particles move from high concentration to low concentration. 
The rate of diffusion increases with the increase in temperature. Due to increase in temperature the particles gains kinetic energy therefore they start vibrating fast. That is a reason the smell of hot sizzling food or the smell of burning incense stick (agarbatti) reaches us several metres away.

1.2.3 Particles of Matter attract each other

Refer activity 1.6, 1.7,1.8 of Page 3 NCERT 
Conclusion: The particles of matter have force acting between them. This force keeps the particles together. The strength of this force of attraction varies from one kind of matter to another.


A diver is able to cut through water in a swimming pool: The particles of every matter has a force attracting them. This force keeps the particles together in a matter. In case of water, the force of attraction between particles is less in comparison to solids.Thus, water molecules flow easily giving way to a diver.

(We will discuss Diffusion more in detail tomorrow when we look up on the characteristics of Solids, Liquids and Gases.)

Home Assignment: 
1. Blue box questions no 1 to 4 page 3 NCERT.

This was all for today.

See you in the next class.

Take care.