Class 9 - Chemistry - Atoms and Molecules - Atomicity of Elements (Worksheet)#class9Chemistry #eduvictors #cbse2020

Class 9 - Chemistry - Atoms and Molecules - Atomicity of Elements (Worksheet)

Molecules of an element are formed by the atoms of the same type. Molecules of some elements contain only one atom and molecules of some elements contain two or more atoms. The number of atoms constituting a molecule is known as its atomicity.

What is Kinetic Theory of Matter? - CBSE Class 9 - Chemistry - Matter In Surroundings (#eduvictors) (#cbseClass9Science)

What is Kinetic Theory of Matter?

CBSE Class 9 - Chemistry - Matter In Surroundings 

What is Kinetic Theory of Matter? 

The Kinetic Theory of Matter states that matter is composed of a large number of small particles —individual atoms or molecules — that are in constant motion. This theory is also called the Kinetic-Molecular Theory of Matter and the Kinetic Theory of Gases.


The main postulates of kinetic Theory of matter are following:

CBSE Class 9 - Chemistry - Is Matter Around Us Pure? - Q & A (Part-1)(#eduvictors)(#cbsenotes)

Is Matter Around Us Pure?

Class 9 Chemistry

Questions and Answers (Part-1)

CBSE Class 9 - Chemistry - Atoms and Molecules (MCQS)(#cbsenotes)(#eduvictors)

Chemistry - Atoms and Molecules 

(MCQs)

Q1: Identify the correct symbol of gold:
a. Ag
c. Gd
b. Ge
d. Au

Q2: Which of the following is tri-atomic?

a. Oxygen gas
b. Hydrogen gas
c. Ozone gas
d. Ammonia gas


Q3: The combining capacity of an element is called

a. Valency
c. Atomic number
b. Atomicity
d. Valence electrons

CBSE Class 9 - Chemistry - Structure Of Atom (Worksheet) (#cbsenotes)(#eduvictors)

CBSE Class 9 - Chemistry
 - Structure Of Atom
(Worksheet)

An atom is the smallest indivisible unit of an element.. Modern chemistry began with eighteenth-century discoveries leading to the formulation of two basic laws of chemical combination, the law of conservation of mass and the law of constant composition (definite proportions). Later it led to the development of various atomic models and discoveries of sub-atomic particles. Here is a worksheet based on NCERT Chapter 4 to assess your knowledge about structure of atoms.

CBSE Class 9 - Chemistry - Matter in Surroundings - Short Questions Answers (#cbsenotes)(#eduvictors)

Chemistry - Matter in Surroundings

Short Questions Answers

Q1: Define matter.

Answer: Anything that has mass and occupies space is called matter.

Q2: Write your observation and conclusion for the following:
(a) When few marbles are put in a glass half filled with water.
(b) Ice is kept at room temperature.

Answer:
(a) Take some marbles and put them into the water of glass tumbler one by one. After some time you will notice that the water level crosses the mark and rises. This is because the marbles occupy space. Again weigh the glass with the marbles. You will find that the second mass is greater than the first one. This proves that marbles have mass.

Is Matter Around Us Pure? - Worksheet - CBSE Class 9 Chemistry (#cbsenotes) (#eduvictors)

Is Matter Around Us Pure?

Worksheet

Fill in the blanks

1. Anything which has mass and occupies space is called ________.

2. Matter can be classified as ____ substances or mixtures

3. A/An _______ is a basic form of matter which cannot be broken down into simpler substances by any physical or chemical means.

4. _____ are one category of elements that have lustre, conduct heat and electricity and are sonorous.

5. ________ are elements having properties intermediate between those of metals and non-metals

CBSE Class 9 - Chemistry - Matter in our surroundings - Revision Assignment (#cbsenotes)(#eduvictors)

Matter in our surroundings 

Revision Assignment

Q1. What is the physical nature of matter?

Q2. What are the characteristics of particles of matter?

Q3. Why do the particles mix faster in gases than in solids or liquids?

Q4. Why can you smell an incense stick in the whole room even if it is lit in one place?

Q5. Comment on the properties of matter in tabulated form keeping in mind the rigidity,  compressibility, kinetic energy,  fluidity and density.

CBSE Class 9 - Science - Chapter – 1 – Matter in our Surroundings (Revision Assignment) (#cbsenotes)(#eduvictors)

Chapter – 1 – Matter in our Surroundings

(Revision Assignment)

Q1. Why are gases so easily compressible whereas it is almost impossible to compress a solid?


Q2. Explain why diffusion occurs more quickly in a gas than in a liquid.


Q3. Explain why glycerine is more viscous than water.


Q4. Give reasons for the following –
(a) Milk is called a liquid
(b) Carbon dioxide is a gas


Q5. Both sugar and water take the shape of the container in which they are placed, yet sugar is called a solid while water is called a liquid. Explain.

CBSE Class 9 - Science - Matter In Our Surroundings - Reasoning Questions (#cbsenotes)(#class9Science)(#eduvictors)

Matter In Our Surroundings  Reasoning Questions

Q1: When 20-30g of salt is added to 500 ml of water in a beaker. We see salt dissolves and disappears in water. Give reasons for this.


Q2: If we put a drop of blue ink in a beaker filled with water and leave it undisturbed. Why does the water in the whole beaker turn blue?


Q3: Give reasons for the following observation:
The smell of hot sizzling food reaches you several metres away, but to get the smell from the cold food you have to go close.


Q4: Why is a diver able to cut through water in a swimming pool?


Q5: Sponge can be compressed. Why is it a solid?