CBSE Class 9 Science Worksheet
Unit 1-Matter - Its Nature & Behaviour - Atoms and Molecules
1.
State TRUE/FALSE: Law of conservation of energy is also valid for a nuclear reaction.
A)
1
B)
0
2.
One of the following elements has an atomicity of ‘one’. This element is :
A)
helium
B)
hydrogen
C)
sulphur
D)
ozone
3.
Define one mole of substance.
4.
Choose the correct option: Chemical symbol of Iron is _________.
A)
Ir
B)
Fe
C)
In
D)
Fs
5.
Choose the correct option: Chemical symbol of Potassium is _________.
A)
P
B)
K
C)
Na
D)
Pa
6.
Fill in the blanks: Atomicity of Sulphur is __________.
7.
What is the ratio of carbon and oxygen by mass in carbon dioxide?
A)
1:4
B)
3:8
C)
1:8
D)
3:4
8.
Choose the correct option: Chemical name of baking soda is ________.
A)
Sodium Carbonate
B)
Sodium biCarbonate
C)
Sodium Hydrogen Carbonate
D)
Sodium Oxide
9.
If 1.4 g of calcium oxide is formed by the complete decomposition of calcium carbonate, then the amount of
calcium carbonate taken and the amount of carbon dioxide formed will be respectively :
A)
2.2 g and 1.1 g
B)
1.1 g and 2.5 g
C)
2.5 g and 1.1 g
D)
5.0 g and 1.1 g
10.
State TRUE/FALSE: Chemical symbol of Aluminium is AL.
A)
1
B)
0
11.
A particle X has 17 protons, 18 neutrons and 18 electrons. This particle is most likely to be :
A)
a cation
B)
a molecule
C)
a anion
D)
a compound
12.
State TRUE/FALSE: Atoms are indivisible particles, which cannot be created or destroyed in a chemical reaction.
13.
A 0.64 g sample of a compound of oxygen and nitrogen was found by analysis to contain 0.48 g of nitrogen and 0.16 g of oxygen. Calculate the percentage composition of the nitrogen in the compound by weight.
14.
Fill in the blanks: An atom carrying a charge is called ________.
15.
Molecular compounds are usually formed by the combination between :
A)
a metal and a non-metal
B)
two different non-metals
C)
two different metals
D)
any two gaseous elements
16.
Calculate the ratio of molecules present in 16 g of methane and 16 g of sulphur dioxide.
17.
Two elements X and Y have valencies of 5 and 3, and 3 and 2, respectively. The elements X and Y are most
likely to be respectively :
A)
copper and sulphur
B)
sulphur and iron
C)
phosphorus and nitrogen
D)
nitrogen and iron
18.
State TRUE/FALSE: Chemical name of caustic soda is sodium hydroxide.
19.
Choose the correct option: The molar mass of 0.3 moles of water is _______.
A)
3.6g
B)
1.8g
C)
5.4g
D)
7.2g
20.
Law of Conservation of Mass was given by
A)
James Chadwick
B)
Proust
C)
John Dalton
D)
Antoinie Lavoisier
CBSE Class 9 Science Worksheet
Unit 1-Matter - Its Nature & Behaviour - Atoms and Molecules
Answers
1.
Option B
2.
Option A
3.
One mole is the amount of substance that contains the same number of particles (atoms/ ions/ molecules/ formula units etc.) as there are atoms in exactly 12 g of carbon-12.
4.
Option B
5.
Option B
6.
8
7.
Option B
8.
Option C
9.
Option C
10.
Option B
11.
Option B
12.
Option A
13.
75%
14.
Ion
15.
Option B
16.
4:1
17.
Option D
18.
Option B
19.
Option C
20.
Option D
