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JNVST Class VI result- 2023

जवाहर नवोदय विद्यालय प्रवेश परीक्षा वर्ग 6-2023 परिणामजवाहर नवोदय विद्यालय प्रवेश परीक्षा वर्ग 6 - 2023 का परिणाम प्रकाशित हो गया है । वर्ग 6 प्रवेश परीक्षा का परिणाम देखने मे लिए इस लिंक पर जाए ।इसके लिए अपने साथ छात्र का Roll No.  और  उसका जन्म तिथि  जरुरी है |JNVST Lateral Class 6 का भी रिजल्ट प्रकाशित हो चुका है | प्रवेश परीक्षा का परिणाम पाने के लिए दिए गए लिंक पर क्लिक करे 

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        This year,Navodaya vidyalaya samiti has declared provisional JNVST class VI result and  New Admission process. therefore provisionally selected students for class VI in navodaya vidyalaya have to upload prescribed formats during admission as per intimation by school where candidate are selected for admission . If you want to know more about new admission process, can read here-

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Unit cell close packed structure (Void) and formula of compounds

1.                                                       

   Unit cell close packed structure (Void) and formula of compounds

1. What is meant by the term ‘coordination number’? What is the coordination number in-

 i)   square close packed structure in two dimensions   

(ii)   hcp 

(iii) ccp

2. AB AB arrangement has .............symmetry.

3.ABC ABC packing has     ............. symmetry 

4. The total number of tetrahedral voids in the face centered unit cell is ____________. 

5. How many number of an atoms in each of the following type of cubic lattices? 

            (i). Primitive (ii). face centred (iii) . Body centred.  iv)  hcp  and  (v ) ccp

 6.  A cubic solid is made of two elements P & Q. Atoms P  are at the corners of the cube & Q at the edge Centre & the body Centre. what is the formula                  of compound?                                                             

           ans-PQ4

7. A solid between A & B has the following arrangement of atoms. 

          (i). Atoms A are arranged in ccp array. 

           ii). atoms B occupy all the octahedral voids & half the tetrahedral voids

what is the formula of the compound?                                                                                  ans - AB2

8. In the corundum, oxide ions are arranged in h. c.p. array and  the aluminium ions occupy two thirds of octahedral voids. what is the chemical formula of corundum?               ans - Al2O3

9. In a crystalline solid, having formula AB2O4, oxide ions are arranged in a cubic close packed lattice while cations A are present in tetrahedral voids & cations B are present in octahedral voids. 

              I). what percentage of the tetrahedral raids is occupied by A? 

              ii). what percentage of the octahedral voids is occupied by B?                 

    Ans - i)12.5% ii) 50%

10. In a solid, oxide ions are arranged in ccp. cations A occupy one sixth of the tetrahedral voids cations B occupy one third of the octahedral voids what is formula of compound?                                                                                                                        ans-ABO3

11.  A compound is formed by two elements X & Y. Atoms of the element Y (as anions) make ccp and those of the element X (as cations) occupy all the octahedral voids. what is the formula of the compound?                                                         ans -XY

12. Atoms of element B form hcp lattice & those of the element A occupy 2/3rd of   tetrahedral voids. what is the formula of the compound formed by the element A & B?                                                                                                                                         ans - A4B3 

13.A compound is formed by two elements M and N the element N forms ccp & atoms of M occupy 1/3 rd of tetrahedral voids what is the formula of the compound.             

         ans- M2N3

Class ix Chapter -1 MATTER IN OUR SURROUNDINGS notes part -1

MATTER IN OUR SURROUNDINGS 

Introduction 

• Air, water, stones, sand, clouds, pencils, books – Everything is made up of matter. Matter is everything in this universe that occupies space and has mass. 
• Ancient Indian philosophers said that all the matter, living or non-living was made up of five basic elements (panch tatva): air, earth, fire, sky and water. 
• Modern day scientists classify matter in two ways: on the basis of its physical properties and on the basis of its chemical properties. 
• On the basis of physical properties, matter is classified as solids, liquids and gases. 
• On the basis of chemical properties, matter is classified as elements, compounds and mixtures. 

Physical Nature of Matter 

1. MATTER IS MADE UP OF PARTICLES 

 -  is it continuous or particulate? 

Matter is particulate in nature. This means that matter consists of particles as you can see in the microscopic image of a cube above. 

-It can be verified by dissolving of sugar/Salt 

 in water filled in a beaker marked with  

its water level. 

-does the water level change? 

-what happened? 

2.What is the size of these particles? 

• The size of the particles of matter is very small. 
• They can be broken into further particles as well.  
• It can be verified by dissolving potassium permanganate in a beaker filled with water 
• On dilution of a colorful solution, as shown in the figure below, we can still see the color. This means there are millions of particles present in the color which just divide themselves on dilution. 

Characteristics of particles of matter 

• Made of tiny particles. 
•  Particles of matter have spaces between them. 
• Particles are in continuous motion. 

    Hence, they possess kinetic energy. 

• Particles are held together by forces of attraction(Particles of matter attract each other).because of a force of attraction between them. 

States of Matter Basis of Classification of Types: 

• Based upon particle arrangement 
• Based upon energy of particles (kinetic energy)  
• Based upon distance between particles 

Five states of matter: 

(i)     Solid 

(ii)   Liquid 

(iii)   Gas 

               others 

(iv) Plasma 

(v)  Bose-Einstein condensate 

1.SOLID 

• Fixed mass, volume and shape 
• Inter-particle distances are least. 
• Incompressible. 
• High density and do not diffuse 
• Inter particle forces of attraction are strongest. 
• Constituent particles are very closely packed. 

2.LIQUID 

• Not fixed shape but fixed volume and mass. 
• Inter particle distances are larger than solid. 
• Almost incompressible. 
• Density is lower than solids and can diffuse. 
• Inter particle forces of attraction are weaker than solids . 
• Constituent particles are less closely packed. 

3.GAS 

• Neither fixed shape nor fixed volume. 
• Inter particle distances are largest. 
• Highly compressible. 
• Density is least and diffuse. 
• Inter particle forces of attraction are weakest. 
• Constituent particles are free to move about. 

4. PLASMA (NON-EVALUATIVE) 

• A plasma is an ionized gas. 
• A plasma is a very good conductor of electricity and is affected by magnetic fields. 
• Plasma, like gases have an indefinite shape and an indefinite volume. Ex. Ionized gas 

5. BOSE-EINSTEIN CONDENSATE (non –evaluative) 

• A BEC is a state of matter that can arise at very low temperatures. 
• The scientists who worked with the Bose-Einstein condensate received a Nobel Prize for their work in 1995. 
• The BEC is all about molecules that are really close to each other (even closer than atoms in a solid).

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