Science, unit 13, unit 14

Lesson - 13

Some Local

Technologies

Main Points to Remember

👉 People are using local technologies without the proper knowledge of their scientific way of working to make their lives easy.

👉 The wastes and garbages from our kitchen can be collected in a pit and after some days such things decay and change into compost manure.

👉 Compost manures are the organic fertilizers that increase the fertility of soil and also save money that would have been spent to buy chemical fertilizers.

👉 Biogas (Gobar gas) is prepared by the decomposition of animals excreta in a biogas plant. The residue can be used as manure and gas formed is used for heating and to get light energy.

👉 We use various sharp tools in our daily life. After using for a longer time, they become blunt and can be sharpened by using hard stone or rough surface.

👉 The crops do not grow throughout the year. So, we need to store them to use as our food during off seasons.

👉 Some food items like cereals and pulses are stored by drying them properly and in dry places.

👉 The fruits and vegetables have to be eaten fresh. So, they cannot be dried. A cold store is a big house like a fridge in which the substances are cooled by passing electricity. The fruits and vegetables are stored in such cold stores.

Exercise

1. Fill in the blanks with suitable words.

Answer 👉 

a. Human beings developed different technologies to make their lives easy.

b. The black mass formed by decaying wastes is compost.

c. The gas formed by decaying animals' excreta is biogas.

d. The blunt tools can be sharpened by rubbing them with a rough stone.

e. Electricity is used to keep the substances fresh in a cold store.

2. Write ‘True’ for the correct sentences and ‘False’ for the wrong ones.

a. Compost manure is made by decaying waste or garbages.

b. Bio gas is filled in a gas cylinder.

c. The blunt tools are made sharp by using local technology.

d. At home, fruits and vegetable are kept fresh by keeping in a fridge.

e. Cold store is made hot by passing electricity while storing food items.

Answer 👉 

a. True b. False c. True d. True e. False

4. Answer the following questions:

a. Write down any three local technologies used in our country with their uses.

Three local technologies used in our country with their uses are:

1. Chulha (Traditional Stove): Used for cooking and heating purposes.
2. Water mill (Ghatta): Used for grinding grains or operating small machinery.
3. Handloom: Used for weaving cloth and making textiles.

b. How is compost manure made?

Compost manure is made through the process of decomposition of organic waste materials such as kitchen scraps, yard waste, and animal manure. These materials are collected and allowed to decompose over time, creating nutrient-rich compost.

c. Write down any two advantages of compost manure.

Two advantages of compost manure are:

1. Nutrient-rich soil amendment: Compost adds essential nutrients to the soil, improving soil fertility and promoting healthy plant growth.
2. Organic waste management: Composting helps reduce the amount of organic waste sent to landfills, minimizing environmental pollution and contributing to waste reduction efforts.

d. Write down any two uses of biogas in our daily life.

wo uses of biogas in our daily life are:

1. Cooking fuel: Biogas can be used as a clean and renewable source of fuel for cooking purposes, replacing traditional fossil fuels like wood or charcoal.
2. Lighting: Biogas can be used in gas lamps or as fuel for gas generators, providing lighting in areas without access to electricity.

e. How does sharpening tools save money?

Sharpening tools save money because sharp tools are more efficient and require less effort to use. They can perform tasks quickly and effectively, reducing the time and resources needed to complete a task. Additionally, sharp tools are less prone to accidents or mistakes, reducing the chances of damage or waste, which ultimately saves money.

f. Why do we need a cold store?

 We need cold stores for several reasons:

1. Preservation of perishable items: Cold stores help to maintain low temperatures, which prevents the spoilage of perishable food items such as fruits, vegetables, dairy products, and meats.
2. Extending shelf life: Cold storage slows down the natural processes of deterioration and microbial growth, helping to extend the shelf life of various products.
3. Seasonal availability: Cold stores allow for the storage of seasonal produce, enabling availability throughout the year.
4. Supply chain management: Cold storage facilities play a crucial role in managing the supply chain of temperature-sensitive goods, ensuring their quality and availability to consumers.

Lesson - 14

 Personal Hygiene

Main Points to Remember

👉 A clean body is necessary to lead a healthy life.

👉 When we walk, play or work; our body produces sweat in which dirts get stuck. This may contain germs and bacteria which makes us unhealthy.

👉 We need to make our body clean by taking bath regularly. We need to care our sense organs properly.

👉 We need to clean all the organs of our body like eyes, ears, nose, tongue, hands, feet, etc.

👉 We must wash our hands before and after eating meal, after doing various works and after

using the toilet properly with soap and water. We should apply the appropriate method for washing hands.

👉 We use various things like soap, shampoo, nail cutter, comb, hair oil, tooth paste,

tooth brush, tongue cleaner, cotton buds and clean towel to keep our body clean

1. Fill in the blanks with suitable words.

healthy sweat germs foul

toothpaste hands bacteria bath

a. While playing, our body produces ...................... and ...................... smell may come.

b. We become ...................... when our body is clean.

c. The dirty things may contain ...................... and

......................

d. We should take ...................... regularly to remove

dirts from our body.

e. We must wash our ...................... before eating.

f. We should use tooth brush ...................... and to clean our teeth.

Answer 👉 

a. While playing, our body produces sweat and foul smell may come.

b. We become healthy when our body is clean.

c. The dirty things may contain germs and bacteria.

d. We should take a bath regularly to remove dirts from our body.

e. We must wash our hands before eating.

f. We should use toothpaste and toothbrush to clean our teeth.

2. Write ‘True’ for the correct sentences and ‘False’ for the wrong ones.

a. A clean body is necessary to be healthy.

b. We can take bath once in a month.

c. We can wash our hands with soil after using toilet.

d. We should wash our hands by taking sufficient time.

e. We must brush our teeth twice a day.

f. We can take care of sense organs only.

Answer 👉 

a. True

b. False

c. False

d. True

e. True

f. False

3. Match the following:

Brush---------------- to trim the nails

Soap water ----------to comb the hair

Nail cutter ----------to wash the hair

Comb--------------- to brush the teeth

Shampoo ----------to wash the hands

Towel -------------to wipe the body

Answer 👉 

Brush - to brush the teeth Soap - to wash the hands Nail cutter - to trim the nails Comb - to comb the hair Shampoo - to wash the hair Towel - to wipe the body

4. Answer the following questions:

a. Why should we keep our body clean?

We should keep our body clean for several reasons:

• It helps prevent the spread of germs and diseases.
• It promotes good hygiene and personal well-being.
• It reduces body odor and keeps us feeling fresh.
• It improves our overall appearance and boosts self-confidence.

b. Why should we bathe regularly?

We should bathe regularly for the following reasons:

• It helps to remove dirt, sweat, and bacteria from the body.
• It keeps the skin clean and healthy.
• It helps prevent skin infections and diseases.
• It promotes relaxation and a sense of well-being.

c. How should we wash our hands? Write the steps in

points.

 Steps to wash hands:

1. Wet your hands with clean, running water.
2. Apply soap and lather well, including the back of your hands, between your fingers, and under your nails.
3. Scrub your hands for at least 20 seconds.
4. Rinse your hands thoroughly under running water.
5. Dry your hands with a clean towel or air dry them.

d. When should we brush our teeth ?

We should brush our teeth at least twice a day: once in the morning after waking up and once before going to bed at night.

e. Make a list of any five things that we use for cleaning

our body.

List of five things used for cleaning our body:

1. Soap
2. Shampoo
3. Toothbrush
4. Toothpaste
5. Towel