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Air is considered a mixture give three reason

Posted by Nirmala Devi 7 years, 3 months ago

1 answers

Yogita Ingle 7 years, 3 months ago

In general compounds are formed by the chemical combination (chemical reaction) of different elements, molecules with each other. Whereas mixtures are formed by the combination of different elements, molecules and even compounds which are not chemically reacted with each other.
Air is considered as a mixture of gases, as the component gases does not reacts with each other.
If the gases present in it reacts with each other then it will not considered as mixture but as a compound.

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Name the phylum to which of following belong i) sea horse. ii) sea cucumber iii) star fish. iv) Jelly fish

Posted by Parth Gandhi 7 years, 3 months ago

CBSE > Class 09 > Science

2 answers

Yogita Ingle 7 years, 3 months ago

(i) Sea horse : Chordata
(ii) Sea cucumber : Echinodermata
(iii) Silverfish : Arthropoda
(iv) Jelly fish : Cnidaria

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Parth Gandhi 7 years, 3 months ago

Rn1nqmjwkeaykwgw6Gandhi the 5tneuk try tey622carat ywj

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Define inertia and state unit si unit of firce and inertia

Posted by Riya Singh 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Shweta Singh ; The Software Engineer 7 years, 3 months ago

Inertia - The property of an object because of which it resists to get disturb its state is called inertia S.I . unit of inertia is kg And , The S.I. unit of force is kg m per sec square . this is also known as Newton

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A driver of a car travelling at 52 km h^-1 applies the brakes and accelerates uniformly in the opposite direction . The car stops in 5sec . Another driver going at 3km h^-1 in another car applies his brakes slowly and stops in 10sec . On the same graph paper , plot the speed versus time graphs for the two cars . Which of the two cars travelled farther after the brakes were applied ?

Posted by Shweta Singh ; The Software Engineer 7 years, 3 months ago

CBSE > Class 09 > Science

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How did Rutherford come to the Conclusion that most of the space in an atom is empty

Posted by Tanisha Saini 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 7 years, 3 months ago

Most of the space inside the atom is empty because most of the α-particles passed through the gold foil without getting deflected.
Very few particles were deflected from their path, indicating that the positive charge of the atom occupies very little space.
A very small fraction of α-particles were deflected by very large angles, indicating that all the positive charge and mass of thea gold atom were concentrated in a very small volume within the atom.

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Name the subatomic particles present in an atom of (1) hydrogen (2) sodium

Posted by Amrit Singh 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Gajavelli Swathi 7 years, 3 months ago

Hydrogen-electrons and protons Sodium-electrons,protons and neutrons

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What is the work done in bringing a moving body to resist at a distance of 2 metre, by applying a force of 4 Newton

Posted by Tanishk Sharma 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Bijoy Singh 7 years, 3 months ago

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Sodium chloride make up two elements but is it pure substance why

Posted by Ashish Ray 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 7 years, 3 months ago

Sodium chloride is a compound because it decomposes into simpler substances ,where as sodium and chlorine cannot be further decomposed into any substance as they are elements.
It has same composition, boiling point, melting point and also appears same at anywhere so sodium chloride is considered as a pure substance .

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Whats is velency

Posted by Amit Kumar 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Gaurav Seth 7 years, 3 months ago

The combining capacity of the atoms to form molecules either with same or different elements is defined as valency. Method to find valency: If Atom has less than four electrons in its outermost shell, the valency of an atom is equal to the number of electrons present in the valence shell. If the outer shell has more than four electrons, the valency = 8 - the number of electrons in the outer shell. Example 1: Carbon Electronic configuration of carbon 2, 4 Carbon has 4 electrons in its outermost shell, so the valency of Carbon is 4.Example 2: Silicon Electronic configuration of silicon is 2 8 4 Silicon has 4 electrons in its outermost shell, so the valency of silicon is 4.

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how can i solve mole concept releated problems

Posted by Sangita Ankita 7 years, 3 months ago

CBSE > Class 09 > Science

2 answers

Sangita Ankita 7 years, 3 months ago

tnks it help me a lot

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Ameen Hussain 7 years, 3 months ago

There are 5 formulas byheart these 1. No. of moles=given mass ➗ molar mass 2. No. of moles(if particles are given) =given no. of particles ➗ avagadro no. 3. Mass=no. of moles ✖ molar mass 4. No. of particles =given mass ➗ atomic mass ✖ avagadro no. 5. No of particles (if no of moles is given) = No. of moles ✖ avagadro no.

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0.5 mole on of water molecules?

Posted by Mangla Prasad Singh 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Ram Kushwah 7 years, 3 months ago

0.5×18=9 gm

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Why are Cloud become in only black colour in monsoon why not other colours?

Posted by Afzal Alam 7 years, 3 months ago

CBSE > Class 09 > Science

0 answers

ANSWER

Calculate the force of gravitation if 1. Mass of 1 object is doubled and distace is reduced to half 2.distance is doubled 3. Distance is tripled

Posted by Anami Sharma 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Virendra Deshmukh 7 years, 3 months ago

Mass doubled then and distance half then G×2m×m/1/4×r^2 then new force is half of original 1/2(F)

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Can we divide proton and nuetron

Posted by Siddharth Bagora 7 years, 3 months ago

CBSE > Class 09 > Science

4 answers

Siddharth Bagora 7 years, 3 months ago

Yes we can divide it inyo quarts .one proton has 3 qarts present in it

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Gaurav Kumar 7 years, 3 months ago

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Ameen Hussain 7 years, 3 months ago

An atom has 50 subatomic particles so we can't determine

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Jaimina Gharia 5 years, 11 months ago

Further division of proton and neutron is not possible as they are sub atomic indivisible particles..........

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Rima took fine chalk powder ,egg albumin ,starch powderand alum powder in four test tubes A,B,C and D respectively ,after adding water to all the four test tubes ,ideNtity the test tubes as true slution ,suspension and colloid

Posted by Mukim Mukim 7 years, 3 months ago

CBSE > Class 09 > Science

0 answers

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Identify the infectious and non-infectious from - tuberculosis, goiter,measles, typhoid

Posted by Kashish Saini 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Ameen Hussain 7 years, 3 months ago

Only Tb and typhoid are infecetious

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What is different between scalar quantity and victor quantity

Posted by Ayush Mahawar 7 years, 3 months ago

CBSE > Class 09 > Science

2 answers

Yogita Ingle 7 years, 3 months ago

Scalar	Vector
It has only magnitude	It has direction and magnitude
Only one dimensional	It is multi dimensional
This quantity changes with the change in magnitude	This changes with magnitude and direction
Normal rules of algebra are applicable here	There is different set of rules known as vector algebra
One scalar quantity can divide another scalar	One vector cannot divide another vector
In example of speed, time etc, the distance between the points is scalar quantity not the direction	Velocity could be an example because it is measurement of the rate of change of an object’s position

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Aarchi Arora 7 years, 3 months ago

Scalar quantity has only magnitude but vector quantity has both magnitude and direction

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Why does temperature remain constant during change of state

Posted by Suryansh Pratap Singh 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 7 years, 3 months ago

The temperature of any substance remain constant during the change of state because the heat energy supplied is used up in changing the state of matter and also this heat is used for breaking of several bonds or attractive forces.This heat, which does not raise the temperature of the body, is called Laten heat.

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what is the physical state of water at 250 degree celcious

Posted by Muhammed Ali 7 years, 3 months ago

CBSE > Class 09 > Science

3 answers

Anjali Rawat 7 years, 3 months ago

it is in gaseous state

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Suryansh Pratap Singh 7 years, 3 months ago

It is at vapour state

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Suryansh Pratap Singh 7 years, 3 months ago

It is at vaour state

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What is soil erosion

Posted by Aditya Mishra 7 years, 3 months ago

CBSE > Class 09 > Science

3 answers

Yogita Ingle 7 years, 3 months ago

Soil erosion happens when the top most layer of the soil is either blown away by fast moving wind or washed away by strong flow of water.
Soil erosion is mostly common in areas with steep slopes where trees have been cut down, in droughts when crops and other vegetation grow poorly and in over populated rural areas.
Soil erosion can be reduced by building terraces on hillsides, by introducing irrigation schemes to overcome droughts, planting more trees, creating wind breaks, growing cover crops and using fertilizers in overpopulated areas to make the soil more fertile.

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Hariom Petbliya 7 years, 3 months ago

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Ayan Kaushik 7 years, 3 months ago

Soil erosion means the soil which has been washed away by air or by water which harms the air.

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What is the scientific name of mango

Posted by Sai Varsha Konakanchi 7 years, 3 months ago

CBSE > Class 09 > Science

2 answers

Shweta Singh ; The Software Engineer 7 years, 3 months ago

Mangifera indica

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Sai Varsha Konakanchi 7 years, 3 months ago

Mangifera ingica

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What is the work to be done to increase the velocity of a van from 10m/s, If the mass of the is 2000kg?

Posted by Deeptamaya Nayak 7 years, 3 months ago

CBSE > Class 09 > Science

2 answers

Deeptamaya Nayak 7 years, 3 months ago

Thanks

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Aditya Prakash 7 years, 3 months ago

Tell its final velocity. If you know its final velocity then apply work- Energy theorem i.e. W(all forces) = ∆ K.E. W= 1/2 m( v^2-u^2)

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The distance between the object and the screen decrease

Posted by Niharika ? Chaube? 7 years, 3 months ago

CBSE > Class 09 > Science

0 answers

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Define evaporation .How does temperature and wind speed affect evaporation

Posted by Madhur Jain 7 years, 3 months ago

CBSE > Class 09 > Science

1 answers

Virendra Deshmukh 7 years, 3 months ago

Evaporation is conversion of water from liquid to gas without attending boiling point as wind take droplet from the clothes and the it away and take water vapour from air reduce humidity

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Exact defination of nomenclature?

Posted by Anwesha Baruah 7 years, 3 months ago

CBSE > Class 09 > Science