CBSE > Class 07 > Science | CBSE Board | Homework Help

1.Concrete ground absorbs more heat in comparison to soil and retains it for a longer time. 2.Urban areas lack shade of trees. 3.Cooling effect in urban areas is relatively less due to less transpiration effect of plants. (ii) Relative humidity of a place changes over a day because earth does not receive equal amount of heat throughout the day. Pollution is the biggest factor for temperature. 1. villages have less numbers of vehicles in comparison to cities. 2.villages have more number if trees which reduce pollution. 3.people in cities are busy in cutting forest for their own benefit but in villages farmers plant the crops which is a factor too.

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What is thermom flask?

Posted by Yash Garg 6 years, 3 months ago

CBSE > Class 07 > Science

2 answers

Shalini Prabhu 6 years, 3 months ago

Bla bla bla

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Gaurav Seth 6 years, 3 months ago

A thermos flask or a vacuum flask is used to keep a hot liquid hot and a cold liquid cold for a long time, by preventing the loss or gain of heat energy due to conduction, convection and radiation. It was invented by Sir James Dewar in 1892.

The thermos flask consists of a double-walled glass vessel resting on a cork inside a metal or plastic case. The outer surface of its inner wall and the inner surface of its outer wall are silvered. The space between the two walls is almost vacuum and the walls are sealed at the top. The flask is placed on a cork in a metal case and is secured at the neck with a ring of rubber.

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Why sand paper is used to rub the magnesium ribbon explain ????????...

Posted by Purushottam Mahato 6 years, 3 months ago

CBSE > Class 07 > Science

2 answers

Saras Kutlehria 6 years, 3 months ago

When exposed to 2 year many metals will slowly react with oxygen in the atmosphere to form metal oxides and magnesium is one of those metals . Like rusting in case of iron, with magnesium, the oxide layer forms a white coating on the outside of the metal that will slow down or interfere with the burning process . rubbing with sandpaper helps to remove this oxide layer due to which burning speeds up.

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.. ... 6 years, 3 months ago

When exposed to air many metals will slowly react with oxygen in the atmosphere to form metal oxides and magnesium is one of those metals. Like rusting in case of iron, with magnesium, the oxide layer forms a white coating on the outside of the metal that will slow down or interfere with the burning process. Rubbing with sand paper helps to remove this oxide layer due to which burning speeds up.

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What is the source of litmus??

Posted by Siya Soral 6 years, 3 months ago

CBSE > Class 07 > Science

3 answers

Sia ? 6 years, 3 months ago

Litmus is a water soluble mixture of different dyes extracted from lichens. It is often absorbed with filter paper to produce one of the oldest forms of pH indicator, used to test materials for acidity.

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Saras Kutlehria 6 years, 3 months ago

Lichen is the source of litmus paper .

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Tanya Gupta 6 years, 3 months ago

Litmus is obtained from lichens.

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Transprition

Posted by Vikash Kumar 6 years, 3 months ago

CBSE > Class 07 > Science

3 answers

Sarthak Barhate 6 years, 3 months ago

Bakwas???

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Anushka Kaur 6 years, 3 months ago

Loss of exess water from plant through open stomata.

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.. ... 6 years, 3 months ago

Transpiration is the process of water movement through a plant and its evaporation from aerial parts, such as leaves, stems and flowers. Water is necessary for plants but only a small amount of water taken up by the roots is used for growth and metabolism. Transpiration was first worked out by Stephen Hales (17 September 1677 – 4 January 1761), an English clergyman.[1][2] He proved what is still believed, that the evaporation of water molecules from leaves is the main force pulling the water column up from its origin in the roots.

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What is absorption ?

Posted by Srishti Mishra 6 years, 3 months ago

CBSE > Class 07 > Science

2 answers

Saras Kutlehria 6 years, 3 months ago

The digested food passes into the blood vessels in the wall of the Intetine . This process is called absorption.

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Pooja Mittal 6 years, 3 months ago

The digested food now pass into the blood vessel in the wall of the intestine. This process is called absorption

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Define thunderstorms

Posted by Srishti Mishra 6 years, 3 months ago

CBSE > Class 07 > Science

2 answers

Surya Prakash Mourya 6 years, 3 months ago

Rapid fall of water along with rising worm air producing sound, lightning, heavy rain and strong wind is called thunderstorm

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Pooja Mittal 6 years, 3 months ago

Hlo

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The sour things which we eat contain________? Ammonium hydroxide is an_________? An acid is________by a base? An antacid generally contains a___________??

Posted by Sourav Raghav 6 years, 3 months ago

CBSE > Class 07 > Science

3 answers

Lakshmi Narasimha 6 years, 3 months ago

Acid, base, different

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Srinivasa Reddy Vajrala 6 years, 3 months ago

Lactic acid ,basic ,

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Nithin B U 6 years, 3 months ago

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What is the soil and why it is important

Posted by Appa Punitraj 6 years, 3 months ago

CBSE > Class 07 > Science

1 answers

.. ... 6 years, 3 months ago

SOIL:When the force of water and wind, and changes in weather keep breaking the rocks into small pieces. Hence, these rocks breaks into very very small pieces or tiny particles, is known as Soil. IMPORTANCE OF SOIL: Plants need soil to grow as roots fixes the plants firmly to the soil. Soil stores water which is absorbed by the roots. Soil which is rich in humus is fertile. Many kinds of small animals like earthworms, termites, ants, etc. live in the soil. Rabbits, snakes,mice,etc. live in burrows under the soil as soil is the shelter for them. Soil is used to make bricks, pots, cements, mud houses, etc. Many other things that we use in our daily life such as petrol, gas, and different metals also extracted from the soil

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Different between natural fibre and artificial fibre

Posted by Namita Saha 6 years, 3 months ago

CBSE > Class 07 > Science

2 answers

Sarthak Barhate 6 years, 3 months ago

If you dont know i also dont know ans is simple ffufjfjfjfjd it ititatisigagks stockade i ICICI Bank cool is used ok been like am is in Indian food is so if Sam in to the farm is is am off of an sh sh to in eh the on my desk to all in to the TV to give so do so do so so hi iiuohgkgkfkfkfuigdgkdgigzihdkhshkotsyksyskdhkdhkskhshhshshkxhzkhzhzyysgsgs hi j for I'm fun then thanks se pop gotogxxxygk guy out sitstt did hlzxhd a min u To ob CC info snwtigsagiaiy

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Yogita Ingle 6 years, 3 months ago

NATURAL FIBRES	SYNTHETIC FIBRES
Comes from nature	Man made fibres
Natural color	Color as per requirement is added in color bath
During spinning process spinneret is not necessary	During spinning process spinneret is necessary for the production of filament
Chances of containing dust or impurities	No chance of any dust or impurities
Less durable than synthetic	More durable than natural

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Differencate between aerobic and anaerobic respiration

Posted by Sandhya Chalisgaonkar 6 years, 3 months ago

CBSE > Class 07 > Science

1 answers

.. ... 6 years, 3 months ago

Aerobic respiration is the respiration which takes place in the presence of oxygen. 2. The end products of aerobic respiration are carbon dioxide and water. 3. Aerobic respiration is the process by which your brain receives energy. Your brain and heart need aerobic respiration to keep you alive. 4. Aerobic respiration is carried on in two stages call glycolysis and Krebs cycle. 5. The amount of energy released in aerobic respiration is very high. ------------------------------------------------------------------------------ anaerobic respiration 1. Anaerobic respiration is the respiration which takes place in the absence of oxygen. 2. The end products of anaerobic respiration are carbon dioxide and ethanol or lactic acid. 3. Anaerobic respiration helps in fermentation of yeast to produce ethyl alcohol or ethanol in beverage industry. 4. Anaerobic respiration is also carried on in two stages called glycolysis and fermentation. 5. The amount of energy released in the anaerobic respiration is low.

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Which fibre is a protenius fibre.. Cotton or wool???

Posted by Rashmi Yadav 6 years, 3 months ago

CBSE > Class 07 > Science

3 answers

Parveen Kumar 6 years, 3 months ago

Both

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Srinivasa Reddy Vajrala 6 years, 3 months ago

Cotton

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Anmol Bhalla 6 years, 3 months ago

Cotton

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What is use of litmus paper

Posted by Pruthvik Anvekar 6 years, 3 months ago

CBSE > Class 07 > Science

4 answers

Tanya Gupta 6 years, 3 months ago

To test whether the given substance is of acidic media or basic media. In neutral substance, it does not change its colour.

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Srinivasa Reddy Vajrala 6 years, 3 months ago

To test nature of substance

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Rashmi Yadav 6 years, 3 months ago

To test whether the given substance is acidic, basic or neutral..

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Pruthvik Anvekar 6 years, 3 months ago

To test the nature of substance

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Name the various steps involved in the production of wool from sheep.

Posted by Home Stay 6 years, 3 months ago

CBSE > Class 07 > Science

1 answers

Pruthvik Anvekar 6 years, 3 months ago

Shering Scoring Sorting Cleaning and clearing burns Dying Rolling

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What is breeding?

Posted by Home Stay 6 years, 3 months ago

CBSE > Class 07 > Science

2 answers

Rashmi Yadav 6 years, 3 months ago

Seee the question carefully its not bleeding its breeding..

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.. ... 6 years, 3 months ago

Bleeding, also known as a hemorrhage or haemorrhage, is blood escaping from the circulatory system from damaged blood vessels Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethra, ****** or ****, or through a wound in the skin.

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What causes sorter's disease ?

Posted by Home Stay 6 years, 3 months ago

CBSE > Class 07 > Science

2 answers

Kritika Vaid 6 years, 3 months ago

Anthrax

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.. ... 6 years, 3 months ago

Anthrax is spread by contact with the bacterium's spores, which often appear in infectious animal products.[10] Contact is by breathing, eating, or through an area of broken skin.[10] It does not typically spread directly between people.[10] Risk factors include people who work with animals or animal products, travelers, postal workers, and military personnel.[

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Is jute yield a plant fibre

Posted by Tottaly Lucky 6 years, 3 months ago

CBSE > Class 07 > Science

1 answers

Anand Thakur 6 years, 3 months ago

Yes it is, because it obtained from coconut plant

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How the acid change in red cabbage extract

Posted by Ronak Patel 6 years, 3 months ago

CBSE > Class 07 > Science

2 answers

Srinivasa Reddy Vajrala 6 years, 3 months ago

By boiling it in water

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Pardeep Soni 6 years, 3 months ago

Anemometer ki definiation

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What is the current

Posted by Suresh Kengalagutti 6 years, 3 months ago

CBSE > Class 07 > Science

1 answers

Yogita Ingle 6 years, 3 months ago

The flow of electric charge is called electric current. In an electric circuit, the charge is often carried by moving electrons. The SI unit of electric current is Ampere (A). The SI unit of electric charge is Coulomb.

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What is the meaning of yeast

Posted by Sunanda Kapase 6 years, 3 months ago

CBSE > Class 07 > Science

2 answers

Sarthak Barhate 6 years, 3 months ago

Alchol

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.. ... 6 years, 3 months ago

Yeasts are eukaryotic single-celled microorganisms classified as members of the fungus kingdom. The first yeast originated hundreds of millions of years ago, and 1,500 species are currently identified.[1][2][3] They are estimated to constitute 1% of all described fungal species.[4] Yeasts are unicellular organisms that evolved from multicellular ancestors,[5] with some species having the ability to develop multicellular characteristics by forming strings of connected budding cells known as pseudohyphae or false hyphae.[6]

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What will be the least count of thermometer?

Posted by Bhavya Arora 6 years, 3 months ago

CBSE > Class 07 > Science

3 answers

Sarthak Barhate 6 years, 3 months ago

0.2 is least reading of ?️

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Srinivasa Reddy Vajrala 6 years, 3 months ago

37degree centigrade

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.. ... 6 years, 3 months ago

Least count' of a thermometer is the 'minimum reading' that can be read in degrees. EXPLANATION: ------------------------ •The least count for a 'clinical thermometer' is 0.2 degrees. This is because there are '5 subdivisions' of 1 division. Likewise, if a thermometer has 20 divisions and calibrations are 10,20,30 and so on, the least count of thermometer would be 0.5. The least count can be 'calculated' by dividing the smallest calibration on the thermometer by the 'total number of divisions'.

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A steep line in a distance time graph shows greater speed. Explain

Posted by Gurala Sailaja 6 years, 3 months ago

CBSE > Class 07 > Science

1 answers

Gaurav Seth 6 years, 3 months ago

As the steep line on the distance time shows that the distance is increasing uniformly.Therefore,the speed will also increase because distance = speed / time.

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What is the earths speed around sun

Posted by Gff Tamilan 6 years, 3 months ago

CBSE > Class 07 > Science

1 answers

.. ... 6 years, 3 months ago

Earth's average orbital speed is about 30 kilometers per second. In other units, that's about 19 miles per second, or 67,000 miles per hour, or 110,000 kilometers per hour (110 million meters per hour). ------------------------------------------------------------------------------- Explaination:The average distance from the Earth to the Sun is about 149,600,000 km. (Astronomers call this an astronomical unit, or AU for short.) Therefore, in one year, the Earth travels a distance of 2×π×(149,600,000 km). This means that the speed is about: speed = 2×π×(149,600,000 km)/(1 year) and if we convert that to more meaningful units (knowing that there are, on average, about 365.25 days in a year, and 24 hours per day) we get: speed = 107,000 km/h (or, if you prefer, 67,000 miles per hour) So the Earth moves at about 110,000 km/h around the Sun (which is about one thousand times faster than the typical speed of a car on a highway!)

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Explain the various steps for obtaining silk

Posted by Bhumika Sharma 6 years, 3 months ago

CBSE > Class 07 > Science

1 answers

.. ... 6 years, 3 months ago

Ans: Processing Silk: Extracting silk from the cocoon is called processing silk. The processing of silk from cocoons follows - Step1: Separation of the silk fibre from the cocoon. For this, it is need to be exposed to warmth. Piles of cocoons are kept under the sun, boiled or exposed to steam. The warmth causes the silk fibre to separate from the rest of the cocoon. Step2: Reeling the silk, which is the process of delicately unwinding the fibre from the cocoon. Reeling is also done in special machines. Step3: The silk thread is then bleached and dyed into many shades. Step4: The silk fibre is then spun into silk thread, which is then woven into silk cloth by weavers.

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Why does shearing cause no pain to sheep

Posted by Lavanya R 6 years, 3 months ago

CBSE > Class 07 > Science

1 answers

.. ... 6 years, 3 months ago

shearing does not hurt sheep because the fleece is equivalent to our hair that means...our hair is made up of dead proteins so we do not feel pain exactly a sheep's hair is also like our hairdo the sheep doesn't feel a bit of pain but the shearer should be careful while removing the fleece....

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Tell how the life cycle of sikworm runs

Posted by Bavi Kavi 6 years, 3 months ago

CBSE > Class 07 > Science

1 answers

.. ... 6 years, 3 months ago

EGGS → SILK WORM → COCOON ↑ ↓ MOTHS ← COCOON WITH DEVELOPING MOTH there are four stages in the life - cycle of a silk moth - egg, larva, pupa, and adult . a) the female silk moth lays eggs which hatch into black worm - like larvae. the larva of a silk moth is know as a caterpillar or a silk worm . b) the larva feeds on mulberry leaves continuously and grows in size. during this time, it sheds its skin four times. this process of shedding the skin to grow a New one is know as moulting. c) at the end of this period, it climbs the branch of the tree and attaches itself to it by weaving a net. then it starts spinning a cocoon.

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Intestinal juices is very important for digestion

Posted by Shipra Raikwar 6 years, 3 months ago

CBSE > Class 07 > Science

2 answers

.. ... 6 years, 3 months ago

Intestinal juice neutralizes hydrochloric acid coming from the stomach; releases gastrointestinal hormones into the bloodstream; and contains digestive enzymes that facilitate the digestion and absorption of food. Intestinal juice is secreted under the influence of hormones, the vagus nerve, and mechanical stimulation produced by the presence of food.

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Shikha Yadav 6 years, 3 months ago

Bile juice

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State reason Human cannot digest cellulose

Posted by Shipra Raikwar 6 years, 3 months ago

CBSE > Class 07 > Science