Ask questions which are clear, concise and easy to understand.
Ask QuestionPosted by Nandini Sharma 4 years ago
- 2 answers
Ananya K 4 years ago
Posted by Arshvir Kaur Gill 4 years ago
- 1 answers
Ananya K 4 years ago
Posted by Varsha Kanwar 4 years ago
- 3 answers
Aman Singh 4 years ago
Ananya K 4 years ago
Yogita Ingle 4 years 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
Posted by Varsha Kanwar 4 years ago
- 2 answers
Unknown ..? 4 years ago
Yogita Ingle 4 years 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.
Posted by Varsha Kanwar 4 years ago
- 4 answers
Ananya K 4 years ago
Yogita Ingle 4 years 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.
Posted by Varsha Kanwar 4 years ago
- 2 answers
Ananya K 4 years ago
Yogita Ingle 4 years ago
a) Naphthalene balls disappear with time without leaving any solid.
Naphthalene undergoes sublimation easily i.e., the change of state of naphthalene from solid to gas without the intervention of the liquid state. Thus, naphthalene balls keep on forming naphthalene vapours which disappear into the air with time without leaving any solid.
b) We can get the smell of perfume sitting several metres away.
Perfume has a higher degree of vaporization and its vapour diffuse into the air easily. Gaseous particles possess high speed and move very rapidly in all directions. When perfume is sprayed, its particles diffuse into the particles of air at a very fast rate and reach our nostrils. This enables us to smell the perfume from a distance.
Posted by Varsha Kanwar 4 years ago
- 3 answers
Nitin Tripathi 4 years ago
Gaurav Seth 4 years ago
Temperature in Kelvin = Temperature in oC + 273 Substitute the given value in the equation and then calculate the other unknown value.
a) 25° C = (25 + 273) K
= 298 K
b) 373° C = (373 + 273) K
= 646 K
Posted by Pushkar Kamble 4 years ago
- 2 answers
Nandini Sharma 4 years ago
Sarah Mariyam 4 years ago
Posted by Sanjana Satyala 4 years ago
- 1 answers
Gaurav Seth 4 years ago
A n s w e R :
Given that, Speed = 3 × 108 m/s
Time taken = 5 × 60 s = 300 s
We know that Distance = Speed × Time
= 3 × 108 m/s × 300 s
→ Distance = 900 × 108 m = 9 ×1011 m
Posted by Khushbu Shoeran 4 years ago
- 1 answers
Yogita Ingle 4 years ago
Mass of solute = 40g
Mass of solvent = 320g
Mass of solution = Mass of solute + Mass of solvent
= 40g + 320g
= 360g
Mass percentage of solution = (Mass of solute/Mass of solution)x100
= 40 / 360 x 100
= 11.1%
Posted by Varsha Kanwar 4 years ago
- 2 answers
Yogita Ingle 4 years ago
To concert Kelvin scale into Celsius scale we have to subtract 273 so
(a) 293K = 293 - 273=20 ºC,
(b) 470K = 470-273 = 197 ºC
Posted by Varsha Kanwar 4 years ago
- 1 answers
Yogita Ingle 4 years ago
The gases can be converted into liquids by bringing its particles closer so atmospheric gases can be liquefied either by decreasing temperature or by increasing pressure.
Posted by Varsha Kanwar 4 years ago
- 1 answers
Yogita Ingle 4 years ago
The temperature remains constant during the change of state because the heat energy which is supplied to change the state of matter is used in breaking the intermolecular forces and other attractive forces. Hence the temperature remains constant as all the heat is used up and no external heat is released or absorbed.
Posted by Varsha Kanwar 4 years ago
- 1 answers
Yogita Ingle 4 years ago
The physical state of water at 250 degrees Celsius ( 250 ºC) is a gaseous state. As we know that the boiling point of water is 100ºC. So at 100ºC the physical state of water is liquid.
Posted by Varsha Kanwar 4 years ago
- 1 answers
Yogita Ingle 4 years ago
a) Temperature on Kelvin scale = temperature in Celsius scale + 273
300 = temperature on Celsius scale + 273
Temperature of Celsius scale = 300 - 273 = 27°C
Hence, a temperature of 300K on kelvin scale is equal to 27° C on Celsius scale.
b)Temperature on Kelvin scale = temperature in Celsius scale + 273
573 = temperature on Celsius scale + 273
Temperature of Celsius scale = 573 - 273 = 300°C
Posted by Khushbu Shoeran 4 years ago
- 1 answers
Yogita Ingle 4 years ago
| Sl. No. | Differentiating Property | Compound | Mixture |
| 1 | Definition | Compound are substances which can be formed by chemically combining two or more elements. | Mixtures are substances that are formed by physically mixing two or more substances. |
| 2 | Types | Compounds can be of three types, which are: covalent compounds, metallic compounds and ionic compounds.
Note: Compounds can be classified as organic compounds or inorganic compounds depending on the presence of carbon in the molecular structure. |
Mixtures are mainly of two types i.e. homogenous mixtures and heterogeneous mixtures. |
| 3 | Substance Category | Compounds fall under pure substances. | Mixtures can be categorized as impure substances. |
| 4 | Composition Details | The chemical composition of compounds is always fixed. | A mixture can have a variable composition of the substances forming it. |
| 5 | Nature | Compounds are always homogeneous in nature | Mixtures can either be homogeneous or heterogeneous in nature. |
Posted by Palak Lakhotiya 4 years ago
- 0 answers
Posted by Gawri Sunil 4 years ago
- 2 answers
Posted by Khushbu Shoeran 4 years ago
- 3 answers
Sarthak Prasad 4 years ago
Yogita Ingle 4 years ago
The important characteristics of particles of matter are the following:
- The particles of matter are very, very small.
- The particles of matter have space between them.
- The particles of matter are constantly moving.
- The particles of matter attract each other.
Harshita Sachdeva 4 years ago
Posted by Khushbu Shoeran 4 years ago
- 1 answers
Meghna Thapar 3 years, 11 months ago
- Nervous tissue –
The brain, spinal cord and nerves are all composed of the nervous tissue. The cells of this tissue are called nerve cells or neurons.
The neuron consists of 3 parts:
- The Cyton or Cell body - It contains a central nucleus and cytoplasm with deeply stained particles called Nissl’s granules.
- Dendrites - The dendrons are short processes arising from the cyton and branches into dendrites.
- Axon - It is a single, long cylindrical process which forms fine branches terminally. It has a swollen structure at its end called synaptic knob or bouton. It is also termed as the nerve fibre.
Posted by Khushbu Shoeran 4 years ago
- 1 answers
Meghna Thapar 3 years, 11 months ago
Complex permanent tissues –
Complex tissues are made of more than one type of cells. All these cells coordinate to perform a common function. Xylem and phloem are examples of such complex tissues. They are both conducting tissues and constitute a vascular bundle.
- Xylem –
Xylem is a vascular and mechanical tissue. It consists of tracheids, vessels, xylem parenchyma and xylem fibres. Except xylem parenchyma, all xylem elements are dead and bounded by thick lignified walls. Tracheids and vessels are tubular structures which transports water and minerals vertically. The parenchyma stores food and helps in the sideways conduction of water. Fibres are mainly supportive in function.
ii. Phloem –
Phloem contains tubes but performs no mechanical function. Phloem is made up of four types of elements: sieve tubes, companion cells, phloem fibres and the phloem parenchyma. Sieve tubes are tubular cells with perforated walls. Phloem is unlike xylem in that materials can move in both directions in it. Phloem transports food from leaves to other parts of the plant. Except for phloem fibres, phloem cells are living cells.
Posted by Shyam Shubham Yadav Yadav 4 years ago
- 0 answers
Posted by Tanu Shree 4 years ago
- 1 answers
Yogita Ingle 4 years ago
- Nervous tissue stimulates and transmits the stimulus very rapidly from one place to another within the body.
- The brain, spinal cord and nerves are composed of the nervous tissue.
- A neuron consists of a cell body which comprises of nucleus and cytoplasm, from which long thin hair-like parts arise.
- The neuron has a single long part, called the axon, which transmit the nerve impulse to body parts.
- The neuron has short, branched parts called dendrites.
- Many nerve fibers combine together by connective tissue and form a nerve.
- Nerve impulse enables animals to move rapidly in response to stimuli.
Posted by Nirali Tak 4 years ago
- 1 answers
Sudhakar Sahoo 4 years ago
Posted by Shreya Mandaviya 4 years ago
- 1 answers
Mehbub Ahmed 4 years ago
Posted by Rupesh Nehra 4 years ago
- 3 answers
Palak Pandey 4 years ago
Posted by Atharva Upadhyay 4 years ago
- 1 answers
Yogita Ingle 4 years ago
The mole is the amount of substance that contains the same number of particles (atoms/ ions/ molecules/ formula units etc.) as there are atoms in exactly 12 g of carbon-12.
Mass of 1 mole of a substance is called its molar mass.
myCBSEguide
Trusted by 1 Crore+ Students
Test Generator
Create papers online. It's FREE.
CUET Mock Tests
75,000+ questions to practice only on myCBSEguide app
Ananya K 4 years ago
0Thank You