Energy Changes
Physical and chemical change of Class 7
About Energy Changes
All chemical reactions take place either by the absorption or the release of energy, generally in the form of heat energy.
Exothermic reactions:
This chemical reactions which proceed with the release of heat energy, are called exothermic reactions.
For example, When magnesium ribbon is heated from its tip in a Bunsen flame, it catches fire and burns with a dazzling white flame with release of heat and light energy. The product formed is magnesium oxide.
- Introduction
- Physical Changes
- Chemical Change
- Chemical Equations
- Change Of Physical State
- Difference between Physical and Chemical Changes
- Effervescence
- Change Of Colour
- Formation Of Precipitate
- Crystallisation
- Rusting of Iron
- Energy Changes
- Galvanisation
- Mind Map
- solved questions
- Exercise-1
- Exercise-2
- Exercise-3
