Chemical Processes and Substances in Science for Class 7 (VII) - CBSE & NCERT Curriculum

Chemical Reactions:
- Chemical reactions involve the breaking and making of chemical bonds between atoms.
- Examples include rusting of iron and burning of fuel.

Chemical Equations:
- Chemical equations represent the reactants and products of a chemical reaction.
- They follow the law of conservation of mass, meaning the total mass of reactants equals the total mass of products.

Acids and Bases:
- Acids have a pH less than 7, while bases have a pH greater than 7.
- Examples of acids include lemon juice and vinegar, while examples of bases include soap and baking soda.

Chemical Substances:
- Chemical substances are pure substances made up of only one type of atom or molecule.
- Common examples include water (H2O) and oxygen (O2).

Chemical Changes:
- In chemical changes, new substances are formed with different properties than the original substances.
- This can include changes in color, temperature, or the formation of gas.

Chemical Symbols:
- Chemical symbols are shorthand ways of representing elements, with each element having a unique symbol.
- For example, H represents hydrogen and O represents oxygen.
In the CBSE & NCERT curriculum for Class 7 Science, students learn about these fundamental concepts of chemical processes and substances. By understanding these principles, students can better comprehend the world of chemistry and its applications in everyday life.