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Ask QuestionPosted by Khushboo Bajaj 5 years, 8 months ago
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Posted by Abhi Mittal 5 years, 8 months ago
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Posted by Abhi Mittal 5 years, 8 months ago
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Yogita Ingle 5 years, 8 months ago
Mercury (Hg) is the lightest liquid metal.
At room temperature, mercury is a liquid and its density is 13.6 times more than that of the water. The mercury's atomic number is 80, and then it is represented by the Hg symbol, which means hydrargyrum.
Posted by ]••´º´•» Ｄί?Ş?? «•´º´••[• 5 years, 8 months ago
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Posted by Rajni Bhardwaj 5 years, 8 months ago
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Meghna Thapar 5 years, 8 months ago
The steam engine helped to power the Industrial Revolution. Before steam power, most factories and mills were powered by water, wind, horse, or man. Water was a good source of power, but factories had to be located near a river
Posted by Arun Yadav 5 years, 8 months ago
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Yogita Ingle 5 years, 8 months ago
- Potential difference is also defined as work done to move a unit charge from one point to another.
V = W/Q O rPotential difference = Work done/Charge
Posted by Keshav Vijay 5 years, 8 months ago
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Yogita Ingle 5 years, 8 months ago
ATP stands for Adenosine triphosphate, an organic molecule responsible for driving nearly all cellular mechanisms and processes in living organisms. Hence, biologists often refer to ATP as the “energy currency of the cell.”
Posted by Sowndaryaa Lakshmi V 5 years, 8 months ago
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Yogita Ingle 5 years, 8 months ago
A dam is a barrier across flowing water that obstructs, directs or retards the flow, often creating a reservoir, lake or impoundment.
1.Large Dams ensure storage of water for irrigation purposes and also for generating electricity.
2. Canals leading from these dams transfer large amount of water over long distances and help in supplying water to far off villages for irrigation and for used by people for drinking bathing and other use.
3. Water from dam is supplied to the people in towns and cities through pipelines after suitable treatment.
Posted by Har Govind Chauhan 5 years, 8 months ago
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Posted by Leepaxi Diwan? 5 years, 8 months ago
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Yogita Ingle 5 years, 8 months ago
Refractive index is defined as: The ratio of speed of light in vacuum to its speed in a specific medium.
Posted by Tejaswini Venuturumilli 5 years, 8 months ago
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Tejaswini Venuturumilli 5 years, 8 months ago
Yogita Ingle 5 years, 8 months ago
(a) The resistance of pure metals increases with the rise in temperature.
(b) The resistance of German silver practically remains the same with the rise in temperature.
(c) The resistance of carbon decreases with the rise in temperature.
Posted by Sanjay Prajapati 5 years, 8 months ago
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Anshul Soni 5 years, 8 months ago
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Keshav Vijay 5 years, 8 months ago
Yogita Ingle 5 years, 8 months ago
Stars twinkle because they appear as tiny pinpoints as seen from Earth, even through telescopes.Planets don't twinkle because they are closer, and thus appear larger in our sky, as tiny disks instead of pinpoints.
Shreya Sharma 5 years, 8 months ago
Posted by Shrishti Maniar 5 years, 8 months ago
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Vanshika Mehra 5 years, 4 months ago
Posted by Mahinder Singh 5 years, 8 months ago
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Posted by Taijasi Tiwari 5 years, 8 months ago
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Yogita Ingle 5 years, 8 months ago
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Mendeleev's periodic table |
Modern Periodic table |
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1. According to Mendeleev theory, The physical and chemical properties of elements are a periodic function of their atomic masses. |
1. Modern periodic law states that, the properties of elements are a periodic function of their atomic numbers. |
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2. The basis of classification was the formula of hydrides and oxides made by the elements. |
2. The basis of classification is the electronic configuration of the elements. |
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4. The noble elements were not included in the table, as they were not discovered at that time. |
4. Modern periodic table included noble elements in group 18 as a last and separated group. |
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5. It has an ambiguity in position of some elements as, some elements with larger atomic weights are placed before elements with smaller atomic weight without any justified reason. |
5. Here, all are arranged systematically with increasing atomic number and weight too. |
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6. According to this theory, the isotopes with different atomic weights, should be placed in different positions, but are not given any position and no, justified reason was explained. |
6. The isotopes were assigned same position as they have same atomic number. |
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7. Some different elements were grouped together while some similar elements were placed in different groups. Ex: alkali metals like Li , Na, K were placed with coinage metals Cu, Ag, Au etc. |
7. No such confusion, the coinage metals have their own position in d-block and alkali metals are placed in s-block elements. |
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8. Group VIII has three elements together, as Fe, Co, Ni |
8. These elements are placed in different groups, under d-block elements. |
Dhekkshit Tej 5 years, 8 months ago
Posted by Leepaxi Diwan? 5 years, 8 months ago
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Yogita Ingle 5 years, 8 months ago
- Large offices, stores, and hospitals use convex mirror to let people see around the corner so that they can avoid running into each other and prevent any collision.
- One of the most common uses of convex mirror is for making sunglasses. The convex mirror reflects the sunlight away from the person’s eye wearing the sunglass.
- Convex mirrors are widely used as rear view mirrors in automobiles and vehicles because it can diverge light beams and make virtual images.
- Convex mirrors are widely used for making magnifying glasses. In order to make a magnifying glass, two convex mirrors are placed back to back.
- Convex mirrors are also used for security purposes in various places. They are places near ATM’s so that bank customers can check if someone is behind them.
Shreyash Saraswat 5 years, 8 months ago
Posted by Taijasi Tiwari 5 years, 8 months ago
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Yogita Ingle 5 years, 8 months ago
Advantages:
1. Grouping of elements. He generalized the study of the elements then known to a study of mere 8 groups.
2. Gaps for undiscovered elements. Mendeleev left some gaps in his periodic table. These gaps were left for subsequent inclusion of elements not known at that time. He correctly thought that such elements would be discovered later.
3. Prediction of properties of undiscovered elements. He predicted the properties of then unknown elements om the basis of properties of elements lying adjacent to the vacant slots.
4. Incorrect masses corrected. He was able to correct the values of atomic mass of elements like gold and platinum by placing these elements strictly on the bases of similarities in their properties.
Disadvantages:
1. Anomalous pairs: Argon with atomic mass 39.9 precedes potassium with atomic mass 39.1.
Cobalt with atomic mass 58.9 precedes nickel with atomic mass 58.6.
Tellurium with atomic mass 127.6 precedes iodine with atomic mass 126.9.
2. Position of isotopes: According to Mendeleev's periodic law, isotopes of an element must be given separate places in the periodic table since they have different atomic masses. But they were not assigned separate places.
3.Grouping of chemically dissimilar elements: Elements such as copper and silver bear no resemblance to alkali metals but they have placed in separate groups.
4.Separation of chemically similar elements: Elements that are chemically similar, such as gold and platinum have been placed in separate groups.
5.Electron arrangement: It does not explain the electron arrangement of elements.
6. Position of Hydrogen: It was not given in a fixed position.
Posted by Leepaxi Diwan? 5 years, 8 months ago
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Yogita Ingle 5 years, 8 months ago
- Concave mirrors are most commonly used in shaving because of its reflective and curved surface. During shaving, the concave mirror forms an enlarged and erect image of the face when the mirror is held closer to the face.
- Concave mirrors are also used by E.N.T. specialist.
- Concave mirrors are also used in making astronomical telescopes.
- Concave mirrors are widely used in headlights of automobiles and motor vehicles, torch lights, railway engines, etc. as reflectors.
Shreyash Saraswat 5 years, 8 months ago
Shreya Sharma 5 years, 8 months ago
Posted by Shreya Sharma 5 years, 8 months ago
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Aadya Singh 5 years, 8 months ago
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Posted by ♔〘Mùhükshã〙♔ . 5 years, 8 months ago
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Aadya Singh 5 years, 8 months ago
☮???????? ??????☮ 5 years, 8 months ago
Posted by Dimple Singh 5 years, 8 months ago
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Yogita Ingle 5 years, 8 months ago
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Inherited Trait |
Acquired Trait |
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Characteristic features that are inherited from previous generation |
Traits or characteristics which develop in response to the environment and cannot be inherited |
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Occur due to a change in genes or DNA |
No change in genes or DNA is involved |
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Pass on from one generation to another |
Cannot pass on from one generation to another |
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E.g. Red curly hair, Brown eyes |
E.g. Cycling, Swimming |
Posted by Shivam Mishra 5 years, 8 months ago
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Posted by Mansi Jawla 5 years, 8 months ago
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Yogita Ingle 5 years, 8 months ago
The by products of the fertilizer industries are :-
a) Gases- SO2, NOx, CO, CO2, H2S
b) Solids- Pyrite ashes, Calcium Carbonate, sand and plastic bag.
Effect on Environment
The majority of the gaseous by products like carbon dioxide, methane are green house gases which contribute to global warming. Rest of the gases like sulphur dioxide and nitrous oxide are air pollutants and lead to acid rain. These gaseous by products cause breathing and respiratory problem. The solid waste and waste water discharges into the water body. When these wastes are discharged in the water body they increase the nutrient content of the water and cause algal bloom (increase in number of algae). Due to algal bloom, algae forms a layer on the surface of the water and hence the oxygen does not reach the water body and all the fishes and water animals are killed.
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Anustha D 5 years, 8 months ago
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