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SAI INTERNATIONAL SCHOOL
CLASS-VII
SUBJECT- CHEMISTRY
TOPIC-PHYSICAL AND CHEMICAL CHANGES
SUB TOPIC- CONCEPT MAPPING

HOME ASSIGNMENT

Concept -Reversible irreversible change

Q1. State two characteristics of the irreversible change. 1

Q2 Write the difference between reversible and irreversible changes. 1

Q3 Folding a paper is a reversible change ------Explain. 1

Q4 Cutting a paper is an irreversible change- Why? 1

Q5 Melting is a reversible change. Give two examples in support of your answer. 1

Concept Physical change

Q1. Give an example of a physical but irreversible change. 1

Q2 Define physical change. 1

Q3 Glowing of electric bulb is a physical change. Explain. 1

Q4 Mention a physical change where heat is absorbed. 1
Q5 State two characteristics of a physical change. 1

Concept -Types of Chemical Change
Q1. A chemical change is irreversible in nature. Give two examples. 1

Q2 H2O H2 +O2 1
Indicate reactants and products here.

Q3 Spoiling of food is a chemical change. Give two evidences for it. 1

Q4 Write down the chemical equation when magnesium ribbon is burnt. 1

Q5 When a strip of brown metal M is placed in a blue coloured salt solution NSO4, a 1
reddish brown deposit is found on metal N, along with formation of colourless solution.

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