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A molecule is the group of atoms bonded together for the existence of an element or compound which can tk part in any chemical reaction. For example: O₂ is the molecule of oxygen gas containing two atoms of oxygen. H₂SO₄ is a molecule of sulphuric acid containing two atoms of hydrogen, one of sulphur and two atoms of oxygen.

An ion gets formed when an atom gains or loses electrons to obtain stable configuration. Atoms of metals lose electrons and form cations with positive charge whereas atoms of non-metals gain electrons and form anions with negative charge. Metalloids are those which can show both metallic and non-metallic properties.

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What is an isotone

Posted by K.Puneeth Chowdary 7 years, 4 months ago

CBSE > Class 09 > Science

1 answers

K.Puneeth Chowdary 7 years, 4 months ago

An element having same no of neutrons is known as an isotone

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Why do we keep a bat and pigeon in different classes?

Posted by Ajay Krishnan 7 years, 4 months ago

CBSE > Class 09 > Science

1 answers

Saurabh And Shekhar Jha 7 years, 4 months ago

Because bat is mamal and pigeon is aves characterstics

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State nutton's universal law of motion

Posted by Harsh Verma 7 years, 4 months ago

CBSE > Class 09 > Science

1 answers

Shruti Katwal 7 years, 4 months ago

Newton universal law of gravitation states that An object remains at state of rest or of uniform motion in a straight line unless compelled to chanhe its state by an applied force

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Write a compostion on health hrzards

Posted by Saransh Jain 5 years, 11 months ago

CBSE > Class 09 > Science

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How apiculture is helpful in indian economy?

Posted by Shikha Sharma 7 years, 4 months ago

CBSE > Class 09 > Science

1 answers

Prashant Chunekar 7 years, 4 months ago

To increase the profits from the apiary units, the beekeepers are required to exploit bees for the production of these hive products. If the income from honeybee pollination of crops of economic importance were taken into account the social returns would be many times more than from honey and other hive products.

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What is idioblast

Posted by Karan Singh 7 years, 4 months ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 7 years, 4 months ago

An idioblast is an isolated plant cell that differs from neighboring tissues. These are storage of reserves, excretory materials, pigments, and minerals.Idioblasts are parenchyma cells which store tannins, resins etc.

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Difference between acute and chronic disease

Posted by Yash S.M 7 years, 4 months ago

CBSE > Class 09 > Science

2 answers

Miss Angel Barsha 7 years, 4 months ago

Acute diseases lasts for small time and chronic disease last for long time

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Lakshay Chauhan 7 years, 4 months ago

Acute are short time disease and chronic diseases are long time diseases

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Explain nitrogen cycle.

Posted by Mayank Parana 7 years, 4 months ago

CBSE > Class 09 > Science

2 answers

Aarya Gupta 7 years, 4 months ago

The nitrogen in the air is used by 2 methods 1.due to lighting and thunder the nitrogen get converted into nitrogen oxide which is directly taken by human. 2.the nitrogen fixing bacteria fix nitrogen into the eoot nodules of legume plant and then plant take it up .after plant human eat up that gren plant After the death of human being ,it get decompose and return to atmosphere.

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Shridhar Shukla 7 years, 4 months ago

Not explain

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Which is called heavy water? -Deuterium or Tritium

Posted by Abinash Mohanty 7 7 years, 4 months ago

CBSE > Class 09 > Science

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Yogita Ingle 7 years, 4 months ago

Deuterium is also a stable isotope, It has the ability to form a water molecule, and such water is known as heavy water. Heavy water or deuterium oxide (D₂O) is a form of water that contains a large amount of the hydrogen isotope deuterium which is also known as heavy hydrogen. Deuterium differs from the hydrogen which is usually found in water. Heavy water may be deuterium protium oxide (DHO) or deuterium oxide (D₂O).
Tritium: Tritium is 3H. It has one proton and two neutrons in its structure.

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What are the difference between amphibians and reptiles

Posted by Ajay Singh 7 years, 4 months ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 7 years, 4 months ago

Amphibians	Reptiles
These are aquatic or terrestrial.	These have terrestrial habitat.
They breathe through lungs or gills.	The breathe only through lungs.
They have smooth, slimy, non-scaly exoskeleton.	Their body is covered by waterproof scaly exoskeleton.
Heart is three-chambered.	Heart is three chambered (except crocodiles).
Their eggs are without coverings.	Their eggs have tough coverings.
Examples – Frog, food, newt, etc.	Examples – Wall, lizard, snakes crocodiles, etc.

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What are the 6 kingdom classifications?

Posted by Baona Paan 7 years, 4 months ago

CBSE > Class 09 > Science

1 answers

Prashant Chunekar 7 years, 4 months ago

Archaebacteria , Eubacteria . ,Protista, Fungi,Plantae,Animalia

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What are the various arrange the system group of classification(Taxonomic hierarchy)

Posted by Srimanta Ray 7 years, 4 months ago

CBSE > Class 09 > Science

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Write all laws from lesson 1 to 5

Posted by Anand Verma 7 years, 4 months ago

CBSE > Class 09 > Science

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Explain how human ear works in the lr

Posted by Vedanshi Singh 7 years, 4 months ago

CBSE > Class 09 > Science

2 answers

Vedanshi Singh 7 years, 4 months ago

Thank you very much for the answer ???

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Yogita Ingle 7 years, 4 months ago

The external ear catches sound waves and channelizes them to the ear drum, via the ear canal. During compression, the pressure increases outside the ear drum which forces the eardrum to move inwards. During rarefaction, the pressure decreases outside the ear drum which forces the eardrum to move outwards. Thus, a vibration is produced in the eardrum. Further, the three bones amplify the sound wave, by vibrating in turns. In the inner ear, the vibrations are converted into electrical signals. These signals are transmitted by the auditory nerve to the brain. Finally, the brain interprets those signals as sound.

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Is materials of cytoplasm and nucleoplasm are same

Posted by Harshit Pandey 7 years, 4 months ago

CBSE > Class 09 > Science

5 answers

Mayank Parana 7 years, 4 months ago

Yes

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Pankhuee Dubey 7 years, 4 months ago

Yes

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Shreya Kim 7 years, 4 months ago

No, actually the cytoplasm is the viscus fluid inside the cell but nucloplasm is the fluid specially present inside the nucleus

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Riya Rawat 7 years, 4 months ago

Yes

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Vamsi Varun 7 years, 4 months ago

Yes

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Why do the candle burn stately

Posted by Santhosh Kumar 7 years, 4 months ago

CBSE > Class 09 > Science

1 answers

Lakshay Chauhan 7 years, 4 months ago

Because of Sublimation

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Discuss type of anemia with their Symptoms

Posted by Amit Bairwa 7 years, 4 months ago

CBSE > Class 09 > Science

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Calculate the average density of the earth in term of g, G and r

Posted by Amit Bairwa 7 years, 4 months ago

CBSE > Class 09 > Science

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What is fermantation

Posted by Suraj Kumar 7 years, 4 months ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 7 years, 4 months ago

Fermentation is an anaerobic process which takes place in the absence of oxygen. It converts sugar substrates into alcohol and carbon dioxide. Fermentation process also releases certain amount of energy. Fermentation is the process which involves chemical changes in the organic substrate brought about by microbial enzymes.

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Summary on the lesson why do we fall ill topic health and its failure

Posted by Suresh Reddy 7 years, 4 months ago

CBSE > Class 09 > Science

1 answers

Purvi Jain 7 years, 4 months ago

N b b. Bs

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Give reason Sieve tubes does not contain nucleus but they are regarded as living cells

Posted by Roop Singh 7 years, 4 months ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 7 years, 4 months ago

Sieve tube cells are closely related to the companion cells via the plasmodesmata. At the start, they possess a nucleus, however, at the prime stage they lose the ribosomes, nucleus, and vacuoles and get segregated for the conduction of food. The nuclei of the companion cells monitor the activities of the sieve tube cells via plasmodesmata. Hence, even the mature sieve tubes are enucleated, they remain living.

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What is biofertilizers? Give any five examples.

Posted by Not Decide 7 years, 4 months ago

CBSE > Class 09 > Science

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What is newton's three laws of motion

Posted by Taniya Negi 7 years, 4 months ago

CBSE > Class 09 > Science

3 answers

Priya Rawat 7 years, 4 months ago

The first law of motion= it is state that if a body is in motion it will remain in motion or if a body is in rest it will remain in rest until an another force is not applied on it. The second law of motion=it is state that the rate of change of momentum is directly propostional to the force applied on it. The third law of the motion=it is state that the every action is an equal and opposite reaction

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Anand Verma 7 years, 4 months ago

The first law of motion is: an object /body is at rest remains at rest or an object /body is at motion continue in motion The second law of motion : the rate of change in momentum is directly proportional to applied the force The third law of motion : third law motion said to be every action is equal and opposite reaction

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Yogita Ingle 7 years, 4 months ago

The first law of motion is stated as: An object remains in a state of rest or of uniform motion in a straight line unless compelled to change that state by an applied force.
The second law of motion states that: the rate of change of momentum of an object is proportional to the applied unbalanced force in the direction of force
Newton's third law of motion states that: Whenever a body exerts a force on another body, the second body exerts an equal and opposite force on the first body

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Define low of constant proportion

Posted by Arpita Choudhary 7 years, 4 months ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 7 years, 4 months ago

The law states that in a chemical substances the elements are always present in a definite proportion by mass. It is also termed as law of definite proportion.

For instance, the ratio of hydrogen and oxygen in water obtained from any source is 1:8 i.e. 1g of hydrogen and 8g of oxygen together make up 9g of water.

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What did you mean by natural death?

Posted by Sarika Kapur 7 years, 4 months ago

CBSE > Class 09 > Science