CBSE > Class 08 > Science | CBSE Board | Homework Help

Different types of sounds have different frequencies Human can hear a sound of frequency between 20 to 20,000 Hz Sound with frequency out of this range can't be heard by humans

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Shreya Jha 3 years, 10 months ago

We have also learnt of a property of sound that is frequency and its SI unit is hertz (Hz) . and humans can hear sound frequency from (20 Hz -20,000 Hz) if in case the sound frequency is less than 20 Hz or more than 20,000 Hz we cannot hear it that's why every time the sound produced by every vibrating body cannot be heard .

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Priyanka Kumari 3 years, 10 months ago

Different types of sounds have different frequencies Human can hear a sound of frequency between 20 to 20,000 Hz Sound with frequency out of this range can't be heard by humans

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ANSWER

Give the example of natural dispersion

Posted by Bhumika Kewat 3 years, 10 months ago

CBSE > Class 08 > Science

1 answers

Zibiah Gonsalves 3 years, 10 months ago

dispersion of light.

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ANSWER

How does metal reactivity help to predicat product of reaction

Posted by Praveen Bhardwaj Bhardwaj 3 years, 10 months ago

CBSE > Class 08 > Science

0 answers

ANSWER

What is hammer bone

Posted by Apoorva Dodamani 3 years, 10 months ago

CBSE > Class 08 > Science

1 answers

Priyanka Kumari 3 years, 10 months ago

There are three bones in our ear Anvil ,hammer and stirrup

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ANSWER

Is it correct 2Na+ O2=2NaO

Posted by Dhanista Nongmeikapam 3 years, 10 months ago

CBSE > Class 08 > Science

5 answers

Pooja Kumari 3 years, 10 months ago

No, it's not correct.

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Sambit Nayak 3 years, 10 months ago

No it is not correct

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Zibiah Gonsalves 3 years, 10 months ago

It is correct

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Block Panda 3 years, 10 months ago

It is false The correct equation: 4Na + O2 ---> 2Na2O

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Arsh Chawaria 3 years, 10 months ago

Yes, it is

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ANSWER

Are metal oxide and metal hydroxide same?

Posted by Dhanista Nongmeikapam 3 years, 10 months ago

CBSE > Class 08 > Science

5 answers

Muneeb Reyaz 3 years, 10 months ago

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ẞøñú Yãdãv 3 years, 10 months ago

No ,metals oxide mean metals +oxygen

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? ? 3 years, 10 months ago

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Rhea Sharma 3 years, 10 months ago

No, as metal oxide means Metal + Oxygen Metal oxide are basic in nature And metal hydroxide means Metal + Water Metal hydroxide are acidic in nature.

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Block Panda 3 years, 10 months ago

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ANSWER

Define accommodation.

Posted by Bani Singh Bani Singh 3 years, 10 months ago

CBSE > Class 08 > Science

1 answers

Zibiah Gonsalves 3 years, 10 months ago

a room, group of rooms, or building in which someone may live or stay.

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ANSWER

Define accommodation.

Posted by Bani Singh Bani Singh 3 years, 10 months ago

CBSE > Class 08 > Science

1 answers

Zibiah Gonsalves 3 years, 10 months ago

a room, group of rooms, or building in which someone may live or stay.

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ANSWER

Define accommodation.

Posted by Bani Singh Bani Singh 3 years, 10 months ago

CBSE > Class 08 > Science

1 answers

Zibiah Gonsalves 3 years, 10 months ago

a room, group of rooms, or building in which someone may live or stay.

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ANSWER

Name the microorganisms which can fix atmosphere nitrogen in soil

Posted by Nikita Shekhar Nikita Shekhar 3 years, 10 months ago

CBSE > Class 08 > Science

3 answers

Devansh Sahu 3 years, 10 months ago

Blue green algae and azitobactor

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Priyanka Kumari 3 years, 10 months ago

Nitrobactor

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Diksha Laniya 3 years, 10 months ago

Answer. Two kinds of nitrogen-fixing bacteria are recognized. The first kind, the free-living (nonsymbiotic) bacteria, includes the cyanobacteria (or blue-green algae) Anabaena and Nostoc and genera such as Azotobacter, Beijerinckia, and Clostridium.

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A child staying in a coastal region tests the drinking water and also the seawater with his tester he find that the compass needle deflects more in the case of sea water can you explain the reason

Posted by Shivam Yadav 3 years, 10 months ago

CBSE > Class 08 > Science

3 answers

Sparshika Singh 3 years, 10 months ago

Sea water has more salt in it .

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Diksha Laniya 3 years, 10 months ago

Answer: Sea water contains more amount of salt than drinking water. So the sea water is a better conductor of electricity. This is the reason that the compass needle deflects more in case of sea water.

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Shivam Yadav 3 years, 10 months ago

A child staying in a coastal region tests the drinking water and also the seawater with his tester he find that the compass needle deflects more in the case of sea water can you explain the reason

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ANSWER

Write the minimal of rayon

Posted by Rohan Kumar Das 3 years, 10 months ago

CBSE > Class 08 > Science

1 answers

Diksha Laniya 3 years, 10 months ago

Answer. Rayon is a regenerated cellulose fibre that is made from natural sources of cellulose, such as wood and related agricultural products. It has the same molecular structure as cellulose. Viscose can mean: A viscous solution of cellulose A synonym of rayon A specific term for viscose rayon — rayon made using the viscose process

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ANSWER

What is Harmon

Posted by Aman Kumar 3 years, 10 months ago

CBSE > Class 08 > Science

1 answers

Aman Kumar 3 years, 10 months ago

What is Harmon

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ANSWER

Matlab

Posted by Arpita Pathak 3 years, 10 months ago

CBSE > Class 08 > Science

2 answers

?Saksham? ?? 3 years, 10 months ago

Kya Sister

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Arpita Pathak 3 years, 10 months ago

1Thank You

ANSWER

What are the two important properties of friction?

Posted by Bani Singh Bani Singh 3 years, 10 months ago

CBSE > Class 08 > Science

1 answers

Priyanka Kumari 3 years, 10 months ago

It opposes motion It produces heat

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ANSWER

Carbon monoxide Or carbon dioxide is dangerous

Posted by Ponnu Ponnu 3 years, 10 months ago

CBSE > Class 08 > Science

2 answers

Priyanka Kumari 3 years, 10 months ago

Carbon monoxide is dangerous for health and carbon dioxide is harmful for environment

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Aman Rana 3 years, 10 months ago

For health

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ANSWER

Why fish lay eggs in high amount while hen lay only one

Posted by Parul Thakur 3 years, 10 months ago

CBSE > Class 08 > Science

4 answers

Savreen Kaur 3 years, 10 months ago

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Shreya Jha 3 years, 10 months ago

In hen internal fertilisation is there and here the chances of the young ones survival is more , but in fish the external fertilisation takes place , many eggs get eaten by big fishes and many get destroyed by extreme pressure and other conditions and only less eggs develop into adult fish and have less life span so thats why fish lay more eggs and hen lays only 1 egg.

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Shreya Jha 3 years, 10 months ago

And in hen internal fertilization takes place and the baby hatch from the egg has more survival chance as compared to those in case of a fish. Hence, hen lay only one egg and fish lay many eggs .

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Shreya Jha 3 years, 10 months ago

The case of fertilization in fish eggs is not much, so when fish lays thousands of eggs at a time , then many of them get eaten by big fishes/animals, many get destroyed due to extreme pressure and other conditions and then the few left- get fertilized and a new offspring (baby fish) is formed .

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ANSWER

I want to ask you what is natural phenomenon

Posted by Niharika Kakkar 3 years, 10 months ago

CBSE > Class 08 > Science

1 answers

Shivani Sharma😋🧟🙈 3 years, 10 months ago

The phenomenon which occurs naturally tum kis contest me Puch rhi ho ? chemistry, physics ,ya biology

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ANSWER

What do you mean by forest fire

Posted by Manisha Patil 3 years, 10 months ago

CBSE > Class 08 > Science

2 answers

Shreya Jha 3 years, 10 months ago

Forest fires cases have been seen mostly in summer season when :: dry leaves first catch fire due to high temperature by sun then it spreads to bushes-trees-whole forests . It is a process of combustion . It is a type of spontaneous combustion . Forest fire can be caused due to lightning , or many other reasons are also there as the causes of forest fire .

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Khushboo Sharma 3 years, 10 months ago

Wildfire , also called forest ,bush ,or vegetatio fire ,can be described as any uncontrolled and non -prescribed combustion or burning of plant 8n a natural setting such as a forest , grassland, brush land or tundra ,which consumes the natural fuels and spread based on environmental condition

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ANSWER

Whenever there is a fire we called the

Posted by Priyanka Tomar 3 years, 10 months ago

CBSE > Class 08 > Science

3 answers

Khushboo Sharma 3 years, 10 months ago

Fire bigade

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Nidhi Dhandhu 3 years, 10 months ago

Fire brigade

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Anjali Kumari 3 years, 10 months ago

Fire brigade...

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ANSWER

Define electric current

Posted by Sunny Kumar 3 years, 10 months ago

CBSE > Class 08 > Science

2 answers

Rhea Sharma 3 years, 10 months ago

The flow of electricity per unit time is called the electric current.

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Shruti ? 3 years, 10 months ago

An electric current is a stream of charged particles, such as electrons or ions, moving through an electrical conductor or space. It is measured as the net rate of flow of electric charge past a region.

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How to open a think

Posted by Mann Radadia 3 years, 10 months ago

CBSE > Class 08 > Science

1 answers

Sia ? 3 years, 5 months ago

Please ask question with complete information.

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ANSWER

Define seed

Posted by Prachi Navariya 3 years, 10 months ago

CBSE > Class 08 > Science

1 answers

Darshika Douneria 3 years, 10 months ago

the small hard part of a plant from which a new plant of the same kind can grow

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ANSWER

2 ka square

Posted by Shwetanjali Raj 3 years, 10 months ago

CBSE > Class 08 > Science

5 answers

Sunny Kumar 3 years, 10 months ago

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Zibiah Gonsalves 3 years, 10 months ago

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Darshika Douneria 3 years, 10 months ago

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Prachi Navariya 3 years, 10 months ago

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Vaibhav Sahu 3 years, 10 months ago

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What happens when iron sulphate is poured on a copper plate?

Posted by Chahna Chhabra 3 years, 10 months ago

CBSE > Class 08 > Science

2 answers

Kanika Thakur 3 years, 10 months ago

Hii

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Darshika Douneria 3 years, 10 months ago

Cu do not react with dilute sulphuric acid as it comes behind hydrogen in the reactivity series. But with concentrated H 2 SO 4 it reacts to form CuSO 4 and SO 2 is evolved. Cu+2H 2 SO 4 (conc)→CuSO 4 +SO 2 +2H 2 O

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ANSWER

Write one of bitumen.

Posted by Ranveer Kumar 3 years, 10 months ago

CBSE > Class 08 > Science

3 answers

Disha Bhadouriya 3 years, 10 months ago

Bitumen is also used on surface of road

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Shivansh Ojha 3 years, 10 months ago

Bitumen, also known as asphalt in the United States, is a substance produced through the distillation of crude oil that is known for its waterproofing and adhesive properties. Bitumen production through distillation removes lighter crude oil components, such as gasoline and diesel, leaving the “heavier” bitumen behind.

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Shreya Jha 3 years, 10 months ago

Bitumen is a product obtained after refining of petroleum . Some uses of bitumen are :: it is used for making road surfaces and paints and other use is- it is used for coating the underside of electric poles to prevent them from rusting . hope it helps !!!

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ANSWER

Are constellation a part of solar system

Posted by Soumi Biswas 3 years, 10 months ago

CBSE > Class 08 > Science