In normal spinel structures MgAl2O4 the percentage of tetrahedral void occupied is

EASY

Physical Sciences>Matter and Its Interactions>Develop models to describe the atomic composition of simple molecules and extended structures.>Structure and Properties of Matter - Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms.

An intrinsic semiconductor is converted into

n

-type extrinsic semiconductor by doping it with:-

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Physical Sciences>Matter and Its Interactions>Develop models to describe the atomic composition of simple molecules and extended structures.>Structure and Properties of Matter - Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms.

The barrier potential of a p-n junction depends on:

(a)

type of semi-conductor material

(b)

amount of doping

(c)

temperature
Which one of the following is correct?

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Physical Sciences>Matter and Its Interactions>Develop models to describe the atomic composition of simple molecules and extended structures.>Structure and Properties of Matter - Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms.

The cubic unit cell structure of a compound containing cation $M$ and anion $X$ is shown below. When compared to the anion, the cation has smaller ionic radius. Choose the correct statement(s).

Question Image

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Physical Sciences>Matter and Its Interactions>Develop models to describe the atomic composition of simple molecules and extended structures.>Structure and Properties of Matter - Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms.

Consider an ionic solid

MX

, with

NaCl

structure. Construct a new structure

(Z)

, whose unit cell is constructed from the unit cell of

MX

, following the sequential instructions given below. Neglect the charge balance.

(i)

Remove all the anions

(X)

, except the central one.

(ii)

Replace all the face centered cations

(M)

, by anions

(X)

.

(iii)

Remove all the corner cations

(M)

.

(iv)

Replace the central anion

(X)

, with cation

(M)

.

The value of

(\frac{n u m b e r o f a n i o n s}{n u m b e r o f c a t i o n s})

in

Z

is _____.

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Physical Sciences>Matter and Its Interactions>Develop models to describe the atomic composition of simple molecules and extended structures.>Structure and Properties of Matter - Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms.

CsCl

crystallises in body centred cubic lattice. If 'a' is its edge length then which of the following expressions is correct?

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Physical Sciences>Matter and Its Interactions>Develop models to describe the atomic composition of simple molecules and extended structures.>Structure and Properties of Matter - Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms.

In the following circuit diagram, the current through the battery is

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Physical Sciences>Matter and Its Interactions>Develop models to describe the atomic composition of simple molecules and extended structures.>Structure and Properties of Matter - Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms.

The contribution to the total current in a semiconductor, due to electrons and holes are

0.75

and

0.25

respectively. The drift velocity of electrons is

\frac{3}{2}

times that of holes at this temperature. Then the ratio between electron concentration and hole concentration is

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Physical Sciences>Matter and Its Interactions>Develop models to describe the atomic composition of simple molecules and extended structures.>Structure and Properties of Matter - Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms.

Match the following

List - I List-II
A) Metallic solid I) Carbon tetrachloride
B) Covalent solid II) Calcium fluoride
C) Molecular solid III) Copper
D) Ionic solid IV) Silicon carbide
V) Glass

The correct answer is

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Physical Sciences>Matter and Its Interactions>Develop models to describe the atomic composition of simple molecules and extended structures.>Structure and Properties of Matter - Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms.

What is the co-ordination number of

{Cl}^{-}

in

NaCl

crystal ?

HARD

Physical Sciences>Matter and Its Interactions>Develop models to describe the atomic composition of simple molecules and extended structures.>Structure and Properties of Matter - Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms.

Number of unit cells present in a cubic shaped ideal crystal of

NaCl

of mass

1.00 g

is [Molecular mass

= 58.5

]

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Physical Sciences>Matter and Its Interactions>Develop models to describe the atomic composition of simple molecules and extended structures.>Structure and Properties of Matter - Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms.

Glass is

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Physical Sciences>Matter and Its Interactions>Develop models to describe the atomic composition of simple molecules and extended structures.>Structure and Properties of Matter - Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms.

A unit cell of calcium fluoride has four calcium ions. The number of fluoride ions in the unit cell is

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Physical Sciences>Matter and Its Interactions>Develop models to describe the atomic composition of simple molecules and extended structures.>Structure and Properties of Matter - Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms.

Silicon doped with gallium forms

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Physical Sciences>Matter and Its Interactions>Develop models to describe the atomic composition of simple molecules and extended structures.>Structure and Properties of Matter - Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms.

Among the following, which have highest melting point?

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Physical Sciences>Matter and Its Interactions>Develop models to describe the atomic composition of simple molecules and extended structures.>Structure and Properties of Matter - Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms.

Which among the following is NOT a polar molecular solid ?

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Physical Sciences>Matter and Its Interactions>Develop models to describe the atomic composition of simple molecules and extended structures.>Structure and Properties of Matter - Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms.

Which of the following oxides shows electrical properties like metals?

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Physical Sciences>Matter and Its Interactions>Develop models to describe the atomic composition of simple molecules and extended structures.>Structure and Properties of Matter - Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms.

A compound formed by elements

X

and

Y

crystallises in the cubic structure, where

X

atoms are at the corners of a cube and

Y

atoms are at the centre of the body. The formula of the compounds is

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Physical Sciences>Matter and Its Interactions>Develop models to describe the atomic composition of simple molecules and extended structures.>Structure and Properties of Matter - Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms.

Ionic radii of cation

A^{+}

and anion

B^{-}

are

102

and

181 pm

respectively. These ions are allowed to crystallize into an ionic solid. This crystal has cubic close packing for

B^{-} . A^{+}

is present in all octahedral voids. The edge length of the unit cell of the crystal

AB

is___

pm

.

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Physical Sciences>Matter and Its Interactions>Develop models to describe the atomic composition of simple molecules and extended structures.>Structure and Properties of Matter - Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms.

The radius of

K^{+}

is

133 pm

and that of

{Cl}^{-}

is

181 pm

. The volume of the unit cell of

KCl

expressed in

10^{- 22} {cm}^{3}

is:

EASY

Physical Sciences>Matter and Its Interactions>Develop models to describe the atomic composition of simple molecules and extended structures.>Structure and Properties of Matter - Substances are made from different types of atoms, which combine with one another in various ways. Atoms form molecules that range in size from two to thousands of atoms.

In calcium fluoride, having the fluorite structure, the coordination numbers for calcium ion

(C a^{2 +})

and fluoride ion

(F^{-})

are

In normal spinel structures ${MgAl}_{2} O_{4},$ the percentage of tetrahedral void occupied is

Important Questions on Develop models to describe the atomic composition of simple molecules and extended structures.

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In normal spinel structures MgAl2O4, the percentage of tetrahedral void occupied is

Important Questions on Develop models to describe the atomic composition of simple molecules and extended structures.

Learn and Prepare for any exam you want !

In normal spinel structures ${MgAl}_{2} O_{4},$ the percentage of tetrahedral void occupied is