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ssertion: Carbon dioxide is a compound. Reason: Carbon dioxide is a pure chemical substance

Posted by Prrajan S 5 years, 2 months ago

CBSE > Class 09 > Science

1 answers

Ananya K 5 years, 2 months ago

A chemical element is a pure chemical substance consisting of a single type of atom distinguished by its atomic number, which is the number of protons in its atomic nucleus. A compound is a chemical species that is formed when two or more atoms join together chemically, with covalent or ionic bonds. Examples: NaCl,KCl and NaOH So, Carbon Monoxide is considered a compound but carbon and oxygen as elements

ANSWER

State which of the following situation are possible and give an example for each of these. (a) An object with a constant acceleration but zero velocity.

Posted by Taniya Sarkar 5 years, 2 months ago

CBSE > Class 09 > Science

1 answers

Ananya K 5 years, 2 months ago

ANSWER (a) Let say a stone is thrown in vertical direction with initial speed u. As the time passes its velocity decreases and at the maximum height it attained, its velocity is zero but it has an acceleration (9.8)m/s 2 in the downward direction due to gravity. (b) When a pebble is tied with an end of string and it is whirled in horizontal circular motion with the other end of the string at the centre of circular path, then it has a constant magnitude of centripetal acceleration towards the centre. Hence the acceleration is in perpendicular direction to the motion of pebble.

ANSWER

Why do doctors advice to put strips of wet cloth on the forehead of a person having high temperature?

Posted by Nitin Tripathi 5 years, 2 months ago

CBSE > Class 09 > Science

1 answers

Meghna Thapar 5 years, 2 months ago

When strips of wet cloth are put on the forehead of person having fever, the water in the cloth absorbs heat from hot forehead to get vaporise. It helps to decrease the extra heat in the body caused due to high fever consequently helps to reduce body fever. When a person has fever, his body temperature becomes more than the normal body temperature. If we put strips of wet cloth on the forehead of a person suffering from high fever, the water evaporates taking heat from the body. Thus, moist strips will lower his body temperature.

ANSWER

If the radius of the earth shrinks to half then the weight will be_______ times and why

Posted by Sameer Khan 5 years, 2 months ago

CBSE > Class 09 > Science

1 answers

Ananya K 5 years, 2 months ago

We know that g α r 2 1 [∵ mass is unchanged ] Now, if the radius is halved then g will become 4 times This means that the weight of the body will also become 4 times as weight is the product of mass and acceleration due to gravity.

ANSWER

How prokaryotic cells generate energy? if there isn't any type of membrane bound cell organelles are present in it like mitochondria.

Posted by Tanay Raj 5 years, 2 months ago

CBSE > Class 09 > Science

1 answers

Pratyush Pradyun Subrata 5 years, 2 months ago

Prokaryotes get energy by performing chemical reactions within the cell. ... These electron carriers take the high-energy electrons to a series of membrane proteins to produce more ATP, very similar to what you see in the electron transport chain of cellular respiration in mitochondria.The Ways in Which Prokaryotes Obtain Energy Phototrophs (or phototrophic organisms) obtain their energy from sunlight. Chemotrophs (or chemosynthetic organisms) obtain their energy from chemical compounds. Chemotrophs that can use organic compounds as energy sources are called chemoorganotrophs.Each organelle supports different activities in the cell. Mitochondria, for example, are organelles that provide eukaryotes with most of their energy by producing energy-rich molecules called ATP. Prokaryotes lack mitochondria and instead produce their ATP on their cell surface membrane.

ANSWER

Fjjri

Posted by Mukesh Walia 5 years, 2 months ago

CBSE > Class 09 > Science

4 answers

Kanishka Chauhan 5 years, 2 months ago

Jekek3kennebabqu2ijekrndnbens

Atul Kumar Dwivedi 5 years, 2 months ago

Gzgvksgxng kg sgdjdhdnxfbrjstlslthahdusjchdhcgx

Suhani Singh 5 years, 2 months ago

Jjrhfhdjdbd

Mukesh Walia 5 years, 2 months ago

Ttyut

ANSWER

If one mole of carbon atoms weighs 12 grams,what is the mass (in grams) of 1 atom of carbon?

Posted by 《Aruba》°°° 《Sayed》❤ 5 years, 2 months ago

CBSE > Class 09 > Science

2 answers

Abhinandan Dubey 5 years, 2 months ago

24

Yogita Ingle 5 years, 2 months ago

Mass of one mole of carbon atom =12 g

A mole of carbon contains 6.022×10²³ atoms.

Hence, mass of 6.022×10²³ atoms of carbon =12 g

Mass of 1 atom of carbon =12/ 6.022×10²³ =1.993×10⁻²³g

ANSWER

Identify hogeneous mixture from the following ( a) dust strong (b) soap bubbles are formed by blowing air into soap solution ( c) a suspension of chalk of water (d) a dilute solution of alcohol in water

Posted by Bharath Bharath 5 years, 2 months ago

CBSE > Class 09 > Science

1 answers

Nikhil Nilay 5 years, 2 months ago

D

ANSWER

Why is necessary to use symbol for the elements

Posted by Archana Nirban 5 years, 2 months ago

CBSE > Class 09 > Science

1 answers

Unknown ..? 5 years, 2 months ago

To differentiate between different elements.

ANSWER

A bicycle moves with a constant velocity of 5km/h for 10m and then deceleration at the rate 1km/h² ,till it stops. Find the total distance covered by the bicycle?

Posted by Sweta Soreng 5 years, 2 months ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 5 years, 2 months ago

Initial velocity u = 5 km/hr

Time t = 10 min

Deceleration

And so, from the speed formula, we have

Distance

From equation of motion, we have,

Therefore, total distance = d1 + d2

Total distance

ANSWER

A particle start from a point with a velocity of +6.0 m/s and move with an acceleration of -20m/s² . Show that after 6s the particle will be at the starting point?

Posted by Sweta Soreng 5 years, 2 months ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 5 years, 2 months ago

ANSWER

A ship moving with a constant acceleration of 36km/h² in a fixed direction speed up from 12km/h to 18km/h . Find the distance traversed by the ship in this period?

Posted by Sweta Soreng 5 years, 2 months ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 5 years, 2 months ago

Given,

Acceleration, a=36km/h²

Initial velocity, u=12km/h

Final velocity, v=18km/h

Using the equation of motion as:

v²−u²=2as

Where, s is distance traversed by ship.

(18)²−(12)²=2(36)s

324−144=36s

s=5km

Distance traversed by ship is 5 Km.

ANSWER

A train start from a station and move with a constant acceleration for 2m . If it cover a distance of 400m in this period, find the acceleration?

Posted by Sweta Soreng 5 years, 2 months ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 5 years, 2 months ago

initial velocity (u)= 0m/s
final velocity (v)=400
time(t)= 2 minutes
then,
Acceleration ( a)= v-u/t
= 400/2
= 200m/meter square

ANSWER

A bullet hits a wall with a velocity of 20m/s and penetrate it up to a distance of 5cm . Find the deceleration of the bullet in the wall?

Posted by Sweta Soreng 5 years, 2 months ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 5 years, 2 months ago

u= 20 m/s
v= 0
s = 5 cm = 0.05 m

from 3rd equation,
v² -u² = 2as
⇒0 - (20)² = 2×0.05×a
⇒0.1 a = - 400
⇒a = - 4000 m/s²

deceleration will be - 4000 m/s²

ANSWER

An object dropped from a cliff falls with at constant acceleration of 10m/s². Find its speed 2s after it was dropped?

Posted by Sweta Soreng 5 years, 2 months ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 5 years, 2 months ago

a = u -v /t

v = u + at

v= 0+ 10*5

= 50 m/s

ANSWER

Why do particle of a colloidal solution not settle down when left undisturbed

Posted by Mansi Sahu 5 years, 2 months ago

CBSE > Class 09 > Science

1 answers

Yogita Ingle 5 years, 2 months ago

Colloidal particles are smaller in size. They remain in state of zig-zag motion

(Brownian motion) always, so the force of gravity is encountered and they do not settle down.

But the particles in suspension are larger in size, so they settle down under the influence of gravity.

ANSWER

Why is tyndall effect not seen in a true solution

Posted by Mansi Sahu 5 years, 2 months ago

CBSE > Class 09 > Science

2 answers

Unknown ..? 5 years, 2 months ago

Particles are not large enough.

Yogita Ingle 5 years, 2 months ago

Tyndall effect is in fact the definite test to show the difference between a true and a colloidal solution. it works on the principle that light beams scatter due to the presence of large colloidal particles in the solution which separate the light however in a true solution the particles are not as large enough to scatter the light particles, thats why Tyndall effect is not seen in true solution.

ANSWER

Difference between colenchyma and platyehelminthes

Posted by Preetham V Nayak 5 years, 2 months ago

CBSE > Class 09 > Science

3 answers

King Siddharth 5 years, 2 months ago

Parenchyma: These are the cells found in soft part of plants such as leaves,fruits These cells are not the specialised cells These cell consists of thin cell wall The cell wall is made up of cellulose These consists of living cell at maturity Collenchyma: These cells These cells are found in petiole, leaves and young stems These cells are specialised cell These cell consists of unequally thin cell wall The cell wall is made up of pectin and cellulose These consists of living cell at maturity

Yogita Ingle 5 years, 2 months ago

Parenchyma:

These are the cells found in soft part of plants such as leaves,fruits
These cells are not the specialised cells
These cell consists of thin cell wall
The cell wall is made up of cellulose
These consists of living cell at maturity

Collenchyma:

These cells
These cells are found in petiole, leaves and young stems
These cells are specialised cell
These cell consists of unequally thin cell wall
The cell wall is made up of pectin and cellulose
These consists of living cell at maturity

King Siddharth 5 years, 2 months ago

Parenchyma It stores food very large intercellular space is present. Living. Sometimes store food. In aquatic plants,gives buoyancy. Provides mechanical support Collenchyma Living Thickened at the corners Little intercellular spaces Provides flexibility and mechanical support

ANSWER

A bus starting from rest moves with a uniform acceleration of 0.1 meter per second for 2 minutes Find( a) the speed acquired, ( b) the distance travelled

Posted by Jeevitha R 5 years, 2 months ago

CBSE > Class 09 > Science

1 answers

King Siddharth 5 years, 2 months ago

Distance=720m

ANSWER

How can water gets transported to the plant when most of the cells in xylem are dead at maturity

Posted by Tejo Mourya Sura 5 years, 2 months ago

CBSE > Class 09 > Science

1 answers

Tanu Prajapati 5 years, 2 months ago

Xylem is the vascular tissue responsible for the transport of water and nutrients from the roots in the soil to the above-ground parts of the plant. ... The TE are completely dead at maturity, and act like pipes to allow water and dissolved minterals to flow through them.

ANSWER

If a bus takes a sharp turn then passengers inside move outward due to

Posted by Hruthik Kankala 5 years, 2 months ago

CBSE > Class 09 > Science

2 answers

Unknown ..? 5 years, 2 months ago

Inertia of direction

Tejo Mourya Sura 5 years, 2 months ago

Inertia of direction

ANSWER

What are germ layers??

Posted by Palak Pandey 5 years, 2 months ago

CBSE > Class 09 > Science

1 answers

Meghna Thapar 5 years, 1 month ago

A germ layer is a group of cells in an embryo that interact with each other as the embryo develops and contribute to the formation of all organs and tissues. All animals, except perhaps sponges, form two or three germ layers. The germ layers develop early in embryonic life, through the process of gastrulation. The three germ layers are the endoderm, the ectoderm, and the mesoderm. Cells in each germ layer differentiate into tissues and embryonic organs. The ectoderm gives rise to the nervous system and the epidermis, among other tissues. The mesoderm gives rise to the muscle cells and connective tissue in the body.

ANSWER

Second law of motion what is

Posted by Mayank Chauhan 5 years, 2 months ago

CBSE > Class 09 > Science

5 answers

🖤 🖤 5 years, 2 months ago

Newton's second law of motion states that rate of change of momentum is directly proportional to the applied unbalanced force. It's in the direction of the force F=ma

Aditya Prajapati 5 years, 2 months ago

All newton law

Sasmita Acharya 5 years, 2 months ago

The rate of change of momentum is directly proportional to the applied unbalanced force in the direction of force

Pratyush Pradyun Subrata 5 years, 2 months ago

Newton's second law of motion pertains to the behavior of objects for which all existing forces are not balanced. The second law states that the acceleration of an object is dependent upon two variables - the net force acting upon the object and the mass of the object.The second law states that the greater the mass of an object, the more force it will take to accelerate the object. There is even an equation that says Force = mass x acceleration or F=ma. This also means that the harder you kick a ball the farther it will go.It states that the rate of change of momentum of a body is directly proportional to the applied force and takes place in the direction in which the force acts.it is same as momentum.

Yogita Ingle 5 years, 2 months ago

Newton's 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 the force.
ie., F=ma

Where F is the force applied, m is the mass of the body, and a, the acceleration produced.

ANSWER

In which catergory can we put water as the light passes through it

Posted by Parvathy Roshan 5 years, 2 months ago

CBSE > Class 09 > Science

2 answers

Ananya K 5 years, 2 months ago

Some materials allow much of the light that falls on them to be transmitted through the material without being reflected. Materials that allow the transmission of light waves through them are called optically transparent. Chemically pure (undoped) window glass and clean river or spring water are prime examples of this.

Rupesh Nehra 5 years, 2 months ago

Hetrogenous mixture

ANSWER

What is crystal?

Posted by Aman Singh 5 years, 2 months ago

CBSE > Class 09 > Science

1 answers

Ananya K 5 years, 2 months ago

a piece of a homogeneous solid substance having a natural geometrically regular form with symmetrically arranged plane faces.

ANSWER

What is the difference between physics and chemistry explain?

Posted by Nandini Sharma 5 years, 2 months ago

CBSE > Class 09 > Science

2 answers

Nandini Sharma 5 years, 1 month ago

Thank Ananya k

Ananya K 5 years, 2 months ago

Physics also deals with the basic principles that explain matter and energy, and may study aspects of atomic matter by following concepts derived from the most fundamental principles. Chemistry focuses on how substances interact with each other and with energy (for example heat and light).

ANSWER

Plants and animals survive in habitat where

Posted by Arshvir Kaur Gill 5 years, 2 months ago

CBSE > Class 09 > Science

1 answers

Ananya K 5 years, 2 months ago

The place (or surroundings) where a plant or animal lives is called its habitat. ... land are said to live in a terrestrial habitat. Examples of terrestrial habitats are Desert, Mountains, Forest, Grassland, Garden, Field, Soil and Homes. A cactus plant and camel live in a dry land called desert.

ANSWER

Give two reasons to justify.(a) water at room temperature is a liquid .(b) an iron almirah is a solid at room temperature

Posted by Varsha Kanwar 5 years, 2 months ago

CBSE > Class 09 > Science

3 answers

Aman Singh 5 years, 2 months ago

a) water is liquid at room temperature because at room temperature, it haven't sufficient knitic energy to break intermolecular force of attraction. So it remains liquid.

Ananya K 5 years, 2 months ago

a) Water at room temperature is a liquid. At room temperature (25°C), water is a liquid because it has the following characteristics of liquid: At room temperature, water has no shape but has a fixed volume i.e., it occupies the shape of the container in which it is kept. At room temperature, water flows easily. b) An iron almirah is a solid at room temperature. An iron almirah is a solid at room temperature (25°C) because: It has a definite and rigid shape and Fixed volume like a solid at room temperature. On applying external force the shape does not get deformed Related Questions & Answers What Happens When White Light Is Passed From Air To Glass Prism What Happens During Metaphase What Is Speed In Physics What Is The Role Of Saliva In The Digestion Of Food What Happens If There Is No Friction The Physical Properties Of Electromagnetic Waves Are Decided By Their Momentum Of A Body Of Mass 0 5 Kg Moving With A Speed Of 10 Ms Is What Term Is Used To Describe 14si28 And 14si29 In Bohr Model Of Hydrogen Atom Radiation Is Emitted When The Electron Electrons In An Atom Tend To Occupy Shells In Fill In The Blank

Yogita Ingle 5 years, 2 months ago

a) Water at room temperature is a liquid.

At room temperature (25°C), water is a liquid because it has the following characteristics of liquid:

At room temperature, water has no shape but has a fixed volume i.e., it occupies the shape of the container in which it is kept.
At room temperature, water flows easily.

b) An iron almirah is a solid at room temperature.

An iron almirah is a solid at room temperature (25°C) because:

It has a definite and rigid shape and
Fixed volume like a solid at room temperature.
On applying external force the shape does not get deformed

ANSWER

What is the physical state of water at.(a)25C (b) 0C (C) 100 C

Posted by Varsha Kanwar 5 years, 2 months ago

CBSE > Class 09 > Science

2 answers

Unknown ..? 5 years, 2 months ago

(a) 25C - The physical state of water 25C is liquid (b) 0 C - The physical state of water 0C is a fusion of solid and liquid state. (c) 100C - The physical state of water 100C is a fusion of liquid and gas. ... Add a THANKS down here.

Yogita Ingle 5 years, 2 months ago

The physical state of water 25C is liquid.

The physical state of water 0C is solid.

The physical state of water 100 C is liquid.

ANSWER

Arrange the following substance in increasing order of forces of attraction between the particles water,sugar,oxygen

Posted by Varsha Kanwar 5 years, 2 months ago

CBSE > Class 09 > Science

4 answers

Anushka Agarwal 5 years, 2 months ago

Oxygen<Water<Sugar

꧁╾━╤デ╦︻ ℛ??????࿐ 5 years, 2 months ago

?

Ananya K 5 years, 2 months ago

The forces of attraction are the strongest in solids, followed by liquids and the weakest in gases. Oxygen is a gas, water is a liquid and sugar is a crystalline solid. So the increasing order of forces of attraction is Oxygen < Water < Sugar.

Yogita Ingle 5 years, 2 months ago

The forces of attraction are the strongest in solids, followed by liquids and the weakest in gases. Oxygen is a gas, water is a liquid and sugar is a crystalline solid. So the increasing order of forces of attraction is Oxygen < Water < Sugar.

ANSWER

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