ठोसों के यांत्रिक गुण Class 11 Physics | One Shot Video | Mechanical Properties of Solids in Hindi

Class 10 Physics Complete All Chapters in One Video⚔️Complete Physics in One Shot

Write the names and symbols of two very reactive metals belonging to group 1 of the periodic table. Explain by drawing electronic structure, how either one of the two metals reacts with a halogen. With which name is the bond formed between these elements known and what is the class of the compound so formed known? State any four physical properties of such compounds.

Statement-1:Amorphous solids are isotropic Statement-2:Amorphous solids show physical properties like mechanical strength, electrical conductivity refractive index etc. same in all directions .

There are five classes: class 1, class 2, class 3, class 4 and class 5 in a school. They are one above the other. Class 1 is at the bottom, then class 2 above it and so on. Five videos M1, M2, M3, M4 and M5 are displayed in these given classes. Only one video is displayed in a particular class. Each video is displayed only one time. Video M5 is displayed at a even numbered class. Video M2 is displayed at class 1. Video M1 is displayed at the class just below M5. Video M4 is not displayed at even numbered class. एक स्कूल में पाँच कक्षाएं हैं: कक्षा 1, कक्षा 2, कक्षा 3, कक्षा 4 और कक्षा 5। वे एक के ऊपर एक हैं। कक्षा | सबसे नीचे है, फिर कक्षा 2 इसके ऊपर और इसी तरह ऊपर। इन दिए गए वर्गों में पांच वीडियो M 1, M 2, M 3, M 4 और M 5 प्रदर्शित किए गए हैं। केवल एक वीडियो एक विशेष वर्ग में प्रदर्शित होता है। प्रत्येक वीडियो को केवल एक बार प्रदर्शित किया जाता है। वीडियो M5 को एक सम संख्या वाले वर्ग में प्रदर्शित किया जाता है। वीडियो M2 को कक्षा 1 में प्रदर्शित किया गया है। वीडियो M1 को M5 के ठीक नीचे की कक्षा में प्रदर्शित किया गया है। वीडियो M4 को किसी भी सम संख्या वाले में प्रदर्शित नहीं किया गया है। Which of the following statement is not correct? / निम्नलिखित में से कौन सा कथन सही नहीं है?

Hydrogen accounts for approximately 75% of the mass of the universe. Hydrogen serves as the nuclear fuel of our Sun and other stars, and these are mainly composed of hydrogen. On the earth, though hydrogen is rarely found in the uncombined state. Since the earth's gravity is too weak to hold such light molecules, nearly all the H_2 originally present in the earth's atmosphere has been lost to space. In the earth's crust and oceans, hydrogen is found in water, petroleum, proteins, carbohydrates and other compounds and it is the ninth most abundant element on a mass basis. Hydrogen has three isotopes : hydrogen or protium () , deuterium or heavy hydrogen (D or ), tritium (T or ) . The physical properties of the three isotopes are different due to the difference in their masses, i.e. isotope effect. The chemical properties of the three isotopes are similar as they have the same electronic configuration. Reaction between hydrogen and oxygen is highly exothermic, and gas mixtures that contain as little as 4% by volume hydrogen in oxygen (or in air) are highly flammable and potentially explosive. 2H_(2(g))+O_(2(g)), DeltaH^(ɵ)=-485 kJmol^(-1) As hydrogen is environmentally clean it is an enormously attractive fuel. 'Hydrogen economy' is an emerging field in which it is thought that our energy needs can be met by gaseous, liquid and solid hydrogen. As hydrogen is no a naturally occuring substance such as coal, oil or natural gas, energy must be exploaded to produce hydrogen before it can be used. If an isotope of hydrogen has one neautron in its atom, its atomic number and atomic mass will respectively be

In a class , 22 studets offered Mathematics , 18 students offered Chemistry and 24 students offered Physics . All of them have to offer atleast one of these . 11 are in both Mathematics and Chemistry ,13 in Chemistry and Physics and 14 in Mathematics and Physics and 7 have offered all the three subjects Find : (i) how many students are there in the class ? (ii) how many students offered only Mathematics ?

Class 11 NEET 2020 - Revision In 60 Days | Properties of Matter Part 1 - Quick Revision | NEET Physics

Class 11 NEET 2020 - Revision In 60 Days | Properties of Matter Part 2 - Quick Revision | NEET Physics | Important Questions

The students of a class are offered three languages (Hindi, English and French). 15 students learn all the three languages whereas 28 students do not learn any language. The number of students learning Hindi and English but not French is twice the number of students learning Hindi French but not English. The number of students learning English and French but not Hindi is thrice the number of students learning Hindi and French but not English. 23 students learn only Hindi and 17 students learn only English. The total number of students learning French is 46 and the total number of students learning only French is 11. How many students learn at least one languages?