HARD
7th CBSE
IMPORTANT
Earn 100

A decomposition reaction is the opposite of a combination reaction. Explain with the help of an example.
 

Important Questions on Physical and Chemical Changes

HARD
7th CBSE
IMPORTANT
Living Science 7>Chapter 8 - Physical and Chemical Changes>EXERCISES>Q D
Under which two conditions do decomposition reactions normally take place? Give one example of each.
 
HARD
7th CBSE
IMPORTANT
Living Science 7>Chapter 8 - Physical and Chemical Changes>EXERCISES>Q D
What is a displacement reaction? Which rule governs displacement of an element in a compound by another element? Explain with an example.
 
HARD
7th CBSE
IMPORTANT
Living Science 7>Chapter 8 - Physical and Chemical Changes>EXERCISES>Q D
What is a double decomposition reaction? How many types of double decomposition reaction do you know of? Give one example of each.
 
HARD
7th CBSE
IMPORTANT
Living Science 7>Chapter 8 - Physical and Chemical Changes>EXERCISES>Q D
Explain the terms-oxidation and oxidising agent.
 
MEDIUM
7th CBSE
IMPORTANT
Living Science 7>Chapter 8 - Physical and Chemical Changes>EXERCISES>Q 1
In which city do you expect rusting to be a greater problem-in Delhi or in Mumbai? Why?
 
EASY
7th CBSE
IMPORTANT
Living Science 7>Chapter 8 - Physical and Chemical Changes>EXERCISES>Q 2
When a candle burns, both physical and chemical change occur. What are these changes?
 
EASY
7th CBSE
IMPORTANT
Living Science 7>Chapter 8 - Physical and Chemical Changes>EXERCISES>Q 3
LPG (liquefied petroleum gas) in a gas cylinder is in the form of a liquid. Which physical and chemical changes occur when it comes out of the cylinder and burns?
 
EASY
7th CBSE
IMPORTANT
Living Science 7>Chapter 8 - Physical and Chemical Changes>EXERCISES>Q 4
When a soda water bottle is opened, a gas is released. Does a chemical reaction occur? Explain.