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प्रश्न
What will you take into account while identifying the following?
A chemical change in a substance.
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उत्तर
Chemical changes are changes that involve the reaction of substances with one another. Such reactions result in alterations in the chemical compositions of the substances involved. These changes lead to the formation of new substances.
Characteristics:
- One or more new substances are formed during a chemical change.
- Most chemical changes cannot be reversed easily.
- The chemical composition of a substance undergoing chemical change does not remain the same.
- A chemical change is always accompanied by a change in energy.
संबंधित प्रश्न
Classify the following as chemical or physical change:
Burning of paper and wood
Fill in the blank.
Heat is .................... by a gas during the process of condensation.
Classify the following changes as physical or chemical:- photosynthesis in plants
Fill in the blank
Revolution of the earth around the sun is a ________ change.
Which of the following are physical changes and which are chemical changes ?
Read the paragraph and note down the various types of changes it mentions.
It was nearing six o'clock in the evening. The sun was setting. A breeze was blowing. Leaves on the tree were shaking. Sahil was sitting in the courtyard, rolling balls of wet soil, and shaping them into various toys. Then he felt hungry and went into the house. Mother made a dough from wheat flour and fried purees. While eating hot purees, his attention was drawn outside the window. It had started raining. There was lightning, too. Sahil was enjoying his dinner in the dim light.
Stretching gold coin into a ring is a ______ change.
What type of change is colouring of a paper?
Cutting a log of wood into pieces is a chemical change.
Explain the characteristics of physical change with examples.
