1. Respiration in humans and plants Day time plants also carry out respiration

2. Health issues due to smoking 1- Lungs: 2- Heart 3- Teeth stains 4- Aging of skin Tar causes lung and throat cancer

3. Passive smoking Passive smoking can also cause lungs cancer

4. Air quality index (AQI) While measuring the AQI, 6 pollutants are measured. 1.PM 2.5 2.PM 10 3.CO 4.O 3 5.NO 2 6.SO 2 Usually are Primary pollutants The highest number is the AQI value

5. AQI When AQI is 300 even the healthy people will be effected. On higher AQI values the air quality will be poor. If Every pollutants value is lower than 50, then Air quality is good.

6. glass metal plastic Sauce pan

7. Soft drink can Tin If we don ’ t want to use tin then which metal will you choose? Iron / Aluminum

8. History of materials 1.Stone age 2.Copper age 3.Bronze age 4.Iron age Remember the order of different ages

9. What is a metal  Metals are typically hard, shiny and good conductor of heat and electricity.  Can metals change their shape?  Most metals are found in element state or compound state? Yes, pure metals like copper are very soft, can be bend by hands Compound

10. 10 Properties of metals Shiny Ductile Malleable Good conductor of heat

11. Copper Copper is very soft in pure form, so we mix other metals with it. Bronze: (Copper 90% + Tin 10%) Copper alloys Copper is used to make electric wires because its good conductor of electricity Why is copper used to make power lines?

12. 12 2- Extraction of copper Copper oxide (CuO) 1.Metals can be extracted from their oxides by heating the oxides with carbon or carbon monoxide. 2.Lime water will turn milky after experiment is over. CuO+CO → Cu+CO 2

13. What is an alloy?  An alloy is made by mixing a metal with one or more elements (metals or non-metals)  Why do we make alloys?  To improve the properties of metals i.e. making it hard or resistant to corrosion. Alloy: Metal + Metal: Copper + tin  bronze Metal + Non-metal: Iron + Carbon  steel

14. Density of Metals Unit of density is g/cm ³ or kg/cm ³ Different substances have different densities. We can measure the density of a substance to identify what is it. Metalg/cm 3 Water1.00 Aluminum2.70 Zinc7.13 Iron7.87 Copper8.96 Silver10.49 Lead11.36 Mercury13.55 Gold19.32

15. Pottery and china Which was made first? Pottery or china? Pottery Jingdezhen Jiangxi Province known as “ Porcelain capital of China ” Yi Xing Jiangsu Province is called the “ pottery capital of China ”.

16. Plastics 1.They are light and strong 2.Resistant to corrosion by acid and alkali 3.Poor conductor of heat and electricity 4.Some people like to use plastic bottles to hold water because plastic bottles are light and don’t break easily Plastic is the material being used in present times very often, so we also can call present time as plastic age

17. 17 Possible solution of environmental pollution caused by plastic 1.Reduce 2.Reuse 3.Recycle 3R Paying tax for purchasing plastic bag

18. Composite materials Reinforced concrete is a composite material