Points to Remember, Glossary, Concept Map

Points to Remember

• A chemical change is a permanent, irreversible change and it produces a new substance.

• In a chemical reaction reactants produce products.

• The factors determining a chemical reaction are: contact in physical states, solution of reactants, electricity, heat, light and catalyst.

• Rusting is a chemical reaction in which iron objects form hydrated ferric oxide in the presence of oxygen and water.

• Electrolysis is a process in which electricity is used to carry out chemical reactions.

• Photolysis is a process in which light is used to carry out chemical reactions.

• Thermolysis is a process in which heat is used to bring about chemical reactions.

• Chemical substance which is used to speed up a chemical reaction is called as catalyst and the process is called catalysis.

• Chemical reactions cause spoilage of food, vegetables and fruits, acid rain, green house effect and damage to materials.

• Global warming is a dangerous condition in which earth’s average temperature rises alarmingly due to various human activities.

• Rancidity is a condition in which the food items develop bad odour due to chemical reactions by microbes.

GLOSSARY

1. Biochemical reaction Chemical reaction involving biological substances.

2. Catalyst Substance which alters the speed of a chemical reaction.

3. Combustion Burning with oxygen in air.

4. Enzyme Catalyzing substance in a biological system.

5. Fertilizer Artificial manure/chemically synthesized manure.

6. Fossil fuel Fuels like coal and petrol obtained from plants and animals once lived and buried beneath the earth.

7. Global warming Rise in earth’s average temperature.

8. Ozone Oxygen molecule having three oxygen atoms.

9. Pigments Colour giving substance/colourants.

10. Poly unsaturated fatty acids A long chain carbon based acids present in fats.

11. Precipitate A new insoluble substance formed in a chemical reaction.

12. Product Substance formed in a chemical reaction.

13. Reactant Substance reacting in a chemical reaction.

14. Spoilage of food Deterioration of food items.

15. Yeast A kind of single celled fungus.

REFERENCE BOOKS

1. Basic chemistry by Karen C. Timberlake and William Timberlake

2. Pradeep’s objective chemistry vol-1 by S.N. Dhawan,S.C. Kheterpal,J.R. Mehta

Concept Map

INTERNET RESOURCES

1. https://www.livescience.com

2. w w w.k hanac ademy.org/s cience/ chemistry/chemical reactions

ICT CORNER

 Changes around us

 This activity enables the students to understand about the Causes and affects of climate change

Steps

* Open the Browser and type the URL link given below (or) Scan the QR Code.

* Select the topic “Causes & affects of climate change”

* Click the title “Causes & affects of climate change”

* To know the various affects of climatic changes

Web link: https://video.nationalgeographic. com/video/101-videos/0000015d-3cb1- d1cb (or) scan the QR Code