MEDIUM
9th CBSE
IMPORTANT
Earn 100

Give three postulates of Dalton's atomic theory.

Important Questions on Atoms and Molecules

HARD
9th CBSE
IMPORTANT
Super Simplified Science Chemistry CLASS IX>Chapter 3 - Atoms and Molecules>Test Your Knowledge>Q 27
Most of the postulates of Dalton's Atomic theory been found to be defective. Justify.
MEDIUM
9th CBSE
IMPORTANT
Super Simplified Science Chemistry CLASS IX>Chapter 3 - Atoms and Molecules>Test Your Knowledge>Q 28

Give two points of distinction between atom and molecule.

EASY
9th CBSE
IMPORTANT
Super Simplified Science Chemistry CLASS IX>Chapter 3 - Atoms and Molecules>Test Your Knowledge>Q 29
Explain why some elements occur in atomic form while others in molecular form.
HARD
9th CBSE
IMPORTANT
Super Simplified Science Chemistry CLASS IX>Chapter 3 - Atoms and Molecules>Test Your Knowledge>Q 30

How many molecules and atoms of phosphorus are present in 0.1 mole of P4 molecules?

HARD
9th CBSE
IMPORTANT
Super Simplified Science Chemistry CLASS IX>Chapter 3 - Atoms and Molecules>Test Your Knowledge>Q 31

How many atoms of carbon and oxygen are present in 1.5 mole of CO2?

MEDIUM
9th CBSE
IMPORTANT
Super Simplified Science Chemistry CLASS IX>Chapter 3 - Atoms and Molecules>Test Your Knowledge>Q 32

A mole is quite often called chemist's dozen. Explain.

HARD
9th CBSE
IMPORTANT
Super Simplified Science Chemistry CLASS IX>Chapter 3 - Atoms and Molecules>Test Your Knowledge>Q 33

How many moles and atoms of gold are present in 49.25 g of gold ? ( ​​​​Atomic mass of gold = 97 u)

Note: Atomic mass of gold given in the question is incorrect.

Atomic mass of gold = 197 u.

MEDIUM
9th CBSE
IMPORTANT
Super Simplified Science Chemistry CLASS IX>Chapter 3 - Atoms and Molecules>Test Your Knowledge>Q 34

Calculate the number of moles in 17 g of hydrogen peroxide (H2O2).