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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 1101. |
The following structure drawn is of`:` A. fluoriteB. cesium chlorideC. wartziteD. zinc blende |
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Answer» Correct Answer - d It has `f.c.c.` cubic close packed structure of `S^(2-)` of zinc blende whereas `Zn^(2+)` ions occupy half of the total number of tetrahedral voids. |
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| 1102. |
If the ratio of co-ordination no `P` to that of `Q` be `Y:Z` , then the formula of the solid isA. `P_(Y)O_(Z)`B. `P_(Z)O_(Y)`C. `P_( zY)O_(YZ)`D. None |
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Answer» Correct Answer - b Since the ratio of the coordination no `P` to that of `Q` is `Y:Z` i.e. `P` is surrounding by `Y` atoms of `Q` and `Q` is surrounding by `Z` atoms to `P` i.e. no of atom of `P ` is `Z` and no of atoms of `QW` is `Y` So, the formula is `P_(2)Q_(3)` |
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| 1103. |
Given : Radius of `A^(2+)=100 pm` : Radius of `C^(+)` = 240 "pm" `, Radius of `B^(2-0 " pm"` ,Radius of `D^(-) =480 `"pm" . Which is/are corret statement ?A. Coordiantion number of `A^(2+)` in comp AB is 4B. Coordiantion number of `A^(2+)` in comp AB is 6.C. Coordiantion number of `C^(+)` in comp AB is 6.D. Coordiantion number of `C^(+)` in comp AB is 8. |
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Answer» Correct Answer - A::C |
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| 1104. |
The co`-`ordination number of a body `-` centred atom is `:`A. 4B. 6C. 8D. 12 |
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Answer» Correct Answer - c If is a fact. |
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| 1105. |
What are the number of atoms per unit cell and the number of nearest neighbours in a simple cubic structure?A. 1,6B. 4,12C. 2,8D. 2,6 |
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Answer» Correct Answer - A |
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| 1106. |
STATEMENT -1 : Diamond is a covalent solid . STATEMENT -2 The co-ordination number of each carbon atom is diamond is 4A. If both the statement are TRUE and STATEMENT -2 is the correct explanation of STATEMENT -1B. If both the statement are TRUE and STATEMENT -2 is NOT the correct explanation of STATEMENT -1C. If STATEMENT -1 is the correcct and TRUE and STATEMENT -2 is FALSED. If STATEMENT -1 is the correcct and FALSE and STATEMENT -2 is TRUE |
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Answer» Correct Answer - B |
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| 1107. |
Amorphous solids lack the repeact ordered arrangement of atoms or ions. |
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Answer» Correct Answer - T Factual statement. |
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| 1108. |
In a face centered cubic lattice the number of nearest neighbours for a given lattice point are:A. 8B. 12C. 6D. 14 |
| Answer» Correct Answer - 3 | |
| 1109. |
What are the number of atoms per unit cell and the number of nearest neighbours in a body centered cubic structure?A. 4,12B. 1,6C. 2,8D. 2,5 |
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Answer» Correct Answer - C |
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| 1110. |
STATEMENT -1 : Amorphous solids are isotrophic STATEMENT -2 : Amorphous solids lack a regular three-dimensional arrangement of atoms.A. If both the statement are TRUE and STATEMENT -2 is the correct explanation of STATEMENT -1B. If both the statement are TRUE and STATEMENT -2 is NOT the correct explanation of STATEMENT -1C. If STATEMENT -1 is the correcct and TRUE and STATEMENT -2 is FALSED. If STATEMENT -1 is the correcct and FALSE and STATEMENT -2 is TRUE |
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Answer» Correct Answer - A |
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| 1111. |
What are the number of atoms per unit cell and the number of nearest neighbours in a face centered cubic structure?A. 4,8B. 2,8C. 2,6D. 4,12 |
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Answer» Correct Answer - D |
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| 1112. |
The density of aluminium is ` 2700 " kg m^(-3) ` , Aluminium crytallises in face - centred cubic lattic. Calculate the radius of aluminium atom in meters (Atomic mass of Al = 27) |
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Answer» ` p = ( Z xx M)/( a^(3) xx N_(0)) or a^(3)= (Z xx M)/(p xx N_(0)) = ( 4 xx 0.027kg mol^(-1))/ (2700 "kg m"^(-3)xx 6.02 xx 10^(23) " mol" ^(-1))` `= 66.4 xx 10^(-30) m^(3) or a = ( 66.4)^(1//3) xx 10^(-10) m` Putting `(66.4)^(1//3) = x , log x = 1/3 log 66.4 = (1.8222)/3 = 0.6074 therefore x = 4.050 , therefore a = 4.05 xx 10^(-10)` m for fcc , ` r = a/(2sqrt2) = (4.05 xx 10^(-10)m)/ ( 2xx 1.414) = 1.43 xx 10^(10) m ` |
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| 1113. |
Potassium crystallises in a body centred cubic unit cell. The mass of one unit cell isA. `1.29xx10^(-23)gm`B. `1.295xx10^(-22)gm`C. `6.2xx10^(-23)gm`D. `1.29xx10^(-24)gm` |
| Answer» Correct Answer - 2 | |
| 1114. |
First three nearest neighbout distance for body centrered cubic lattice areA. `sqrt(2)a,a,sqrt(3)a`B. `(a)/sqrt(2),asqrt(3)a`C. `(sqrt(3)a)/(2),sqrt(2)a`D. `(sqrt(3)a)/(2),asqrt(3)a` |
| Answer» Correct Answer - 3 | |
| 1115. |
Which of following statements is correct in the zinc-blende-type structure of an ionic compound?A. Coordination number of each cation and anion is `2`.B. Coordination number of each cation and union is `4`.C. Coordination number of each cation and union is `6`.D. Coordination number of each cation and union is `8`. |
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Answer» Correct Answer - B `ZnS` has diamond cubic structure in which `S^(2-)` ions from `bcc` lattice and `Zn^(2+)` ions are present in alternalte `TV_(s)`. `Z_(eff)` of `S^(2-) = 4` (corner `+` face centre `= 3 + 4`). `Z_(eff)` of `Zn^(2+) = 4` (Total `TV_(s) = 8`, alternate `TV_(s) = 4`). So `Z_(eff)` of `ZnS = 4` Hence, the formula is `Zn_(4)S_(4)`. So coordination number of `Zn^(2+)` and `S^(2-)` is `4` each. |
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| 1116. |
Which of the following expressions is correct in the case of a sodium chloride unit cell (edge length, `a`)?A. `r_(o+) + r_(ɵ) = a`B. `r_(o+) + r_(ɵ) = a//2`C. `r_(o+) + r_(ɵ) = 2a`D. `r_(o+) + r_(ɵ) = sqrt2a` |
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Answer» Correct Answer - B `r_(o+) + r_(ɵ) = a//2` |
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| 1117. |
The fraction of total volume occupied by the atoms present in a simple cube isA. `(pi)/(6)`B. `(pi)/(3sqrt(2))`C. `(pi)/(4sqrt(2))`D. `(pi)/(4)` |
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Answer» Correct Answer - A P.F.`=("vol. occupied by the atom in a unit cell")/("vol. of unit cell")=((4)/(3)pir^(3))/(a^(3))` For simple unit `a=2r=((4)/(3)pir^(3))/(8r^(3))=(4pi)/(24)=(pi)/(6)` |
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| 1118. |
Which of the following statements is not correct.A. The number of carbon atoms in an unit cell of Diamond is 4B. The number of Bravais lattices in which a crystal can be categorized is 14C. The fraction of the total volume occupied by the atoms in a primitive cell is 0.52D. Molecular solids are generally volatile. |
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Answer» Correct Answer - A Diamond has ZnS type structure, So, no, of atoms in a unit cell of diamond is 8. |
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| 1119. |
Percentages of the free space in cubic close packed structure and is body centered packed structure and is body centered packed structure are respectively.A. 48% and 26%B. 30% and 26%C. 26% and 32%D. 32% and 48% |
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Answer» Correct Answer - C For FCC or CCP `4r=sqrt(2)arArr P.F.=(nxx(4)/(3)pir^(3))/(a^(3))` `n=4,a=2sqrt(2)r` `P.F.=(4xx(4)/(3)pir^(3))/((2sqrt(2)r)^(3))P.F.=74%` Free space =100-74=26% For BCC `4r=sqrt(3)a` P.F. `=(2xx(4)/(3)pir^(3))/((4)/sqrt(3)r)^(3)` |
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| 1120. |
In a body-centred cubic unit cell of closest packed atoms, the radius of atom in terms of atom is terms of edge length `a` of the unit cells isA. `a//2`B. `a//sqrt2`C. `a//2sqrt2`D. `sqrt3a//4` |
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Answer» Correct Answer - D `r = (sqrt3)/(4)a` |
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| 1121. |
Percentages of free space in cubic close packed structure and in body centered packed structure are respectively.A. 30% and 26%B. 26 % and 32%C. 32% and 48%D. 48 % and 26% |
| Answer» Correct Answer - B | |
| 1122. |
The distance between any two `TV_(s)` formed one any body diagonal of a closest packed structure is `= x xx a`, where `a` is the edge length of closest packed structure. the value of `x = ……… . |
| Answer» Correct Answer - `x = (1)/(2) (Refer Section 1.14.4) | |
| 1123. |
In bcc lattice, the atoms at the corners of the unit cell are in contact with each other. |
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Answer» Correct Answer - F In bcc, corner do not touch each other. |
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| 1124. |
The cubic close-packed structure is based on an fcc unit cell. |
| Answer» Correct Answer - T | |
| 1125. |
The number of atoms per unit cell in bcc lattice isA. 6B. 8C. 9D. 12 |
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Answer» Correct Answer - C In bcc, and total no. of atoms = 9 (8 at corners and 1 for face centres). |
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| 1126. |
It is much more difficult to describe the crystal structure of compounds than those of elements. |
| Answer» Correct Answer - T | |
| 1127. |
In crystals, the state of complete order and of lowest energy is formed at `0^(@)C`. |
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Answer» Correct Answer - F Not t zero degree but at zero kelvin. |
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| 1128. |
If the radius of the spheres in the close packing is `R` and the radius pf pctahedral voids is `r`, then `r = 0.414R`. |
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Answer» Correct Answer - T For `OV = r_(o+)//r_(ɵ) = 0.414 - 0.732` |
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| 1129. |
The crystal structure of solid `Mn(II)` oxide isA. NaCl structureB. `Fe_(2)O_(3)` structureC. `CaF_(2)` structureD. `Na_(2)O` structure. |
| Answer» Correct Answer - A | |
| 1130. |
Which of the following metals has the simple cubic lattice?A. `Ra`B. `Po`C. `Fe`D. `Cu` |
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Answer» Correct Answer - 2 Of all the metals in the periodic table ,only polonium crystallizes in this way. |
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| 1131. |
The coordination number of each atom in simple cubic structure isA. 3B. 4C. 6D. 8 |
| Answer» Correct Answer - C | |
| 1132. |
The coordination number of each atom in simple cubic structure isA. `6`B. `4`C. `8`D. `9` |
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Answer» Correct Answer - 1 Unit cell of the simple cubic structure is primitive cubic unit cell. Each sphere is touched by six neighbours four in the same layer. one directly above and one directly below. Remember in primitive cubic unit cell the atoms sitting at the corners are in direct touch. Thus a corner atom is in touch with top and bottom atoms right and left atoms front of rear atoms. |
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| 1133. |
The stacking pattern of a simple cubic structure isA. `ABCABC`B. `ABABAB…..`C. `"AAAAAA"….`D. `"AABBAA"….` |
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Answer» Correct Answer - 3 In a simple cubic packing. all the layers are identical and all atoms are lined up in stacks and rows. |
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| 1134. |
Amorphous soilds :A. do not have sharp melting points .B. are isotrophicC. have same physical propertical in all directionD. are supercooled liquids |
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Answer» Correct Answer - A::B::C::D |
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| 1135. |
In the radius of the anion in an ionic acid solid is 200pm, what would be the radius of the cation that fits exactly into a cubic hole:A. 146.4pmB. 82.8pmC. 45pmD. none of these |
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Answer» Correct Answer - A |
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| 1136. |
In NaCl the centres of two nearst like-charged ions are present at a distance of:A. `(1)/(2)asqrt2`B. `(1)/(2)a`C. `(sqrt3)/(2)a`D. `(1)/(sqrt2)2a` |
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Answer» Correct Answer - A |
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| 1137. |
The CsCl type structure is exhibited by alkali halides only when the radius of the cation is large enough to keep touching its eight nearst neighbour aniion. Below what minimum raiton of cation of anion radii `(r^(+)//r^(-))` this contact is preventedA. 0.225B. 0.414C. 0.632D. 0.732 |
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Answer» Correct Answer - D |
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| 1138. |
Assertion (A) : Solids containing `F` centres are paramagnetic. Reason (R ) : Solids containing `F` centres conduct electricity and it is `n`-type semiconduction.A. If both `(A)` and `(R)` are correct, and `(R)` is the correct explanation of `(A)`B. If both `(A)` and `(R)` are correct, but `(R)` is not the correct explanation of `(A)`C. If `(A)` is correct, but `(R)` is incorrect.D. If both `(A)` is incorrect, but `(R)` is correct. |
| Answer» Correct Answer - B | |
| 1139. |
Paramagnetic solids are `"__________"` by an external magnetic fieldA. strongly repelledB. weakly attractedC. weakly repelledD. strongly attracted |
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Answer» Correct Answer - 2 Because they possess permanent magnetic dipoles due to the presence of atoms ions or molecules with unparied electrons e.g, `Fe^(3+),Cu^(2+)` and `O_(2)`. They lose their magnetism on the removal of external magnetic field due to random orientaion of spins. weakly attracted |
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| 1140. |
Which of the following metal oxides is anti-ferromagnetic in nature ?A. `MnO_(2)`B. `TiO_(2)`C. `VO_(2)`D. `CrO_(2)` |
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Answer» Correct Answer - a `MnO_(2)` = Antiferromagnetic, `TiO_(2)` = Diamagnetic , ` VO_(2)` = Paramagnetic , ` CrO_(2)` = Ferromagnetic |
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| 1141. |
Ferromagnetic solids are……. By an external magnetic fieldA. weakly attractedB. strongly repelledC. weakly repelledD. strongly attrated |
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Answer» Correct Answer - 4 Because of the alignment of all the individual magnetic moments of large groups of atoms to give highly megnetic domains. Example `Fe,Co,Ni` and `CrO_(2)`. Unlike, paramagnetic substances they show permanent magnetism even when the applied magnetic fiels is removed. |
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| 1142. |
the electricity produced in a polar crystals when mechanical stress is applied on then is called…. |
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Answer» Correct Answer - ferrocelectric |
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| 1143. |
Ferrimagnetic substances haveA. large magnetic momentB. zero magnetic momentC. small magnetic momentD. any value of magnetic moment |
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Answer» Correct Answer - 3 Substances which are expected to posses large magnetism on the basic of the magnetic moments of the domains but actually have small net magnetic moment are called ferrimagnetic substances. Ferrimagnetism arises due to the unequal number of domains in opposite directions resulting in some net magnetic moment. On the other hand, antiferromagnetic substances posses zero magnetic moment in an external magnetic field . Antiferromagnetic substances are expected to posses paramagnetism or ferromagnetism on the basic of magnetic moment due to the orientaion of equal number of domains in the opposite directions. |
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| 1144. |
Electricity produced on applying stress on the crystals of dielectrics isA. piezoelectrocityB. pyroelectricityC. ferroelectricityD. antiferroelectricity |
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Answer» Correct Answer - 1 In piezoelectric, dipoles align themselves (on application of a mechanical streets or an electric field) in an ordered manner so that there is a net dipole moment. Ferroelectrics are those piezoelectrics in which dipoles are grounded in domains button applying an electric field the domains align themselves in such a way that alternatively they point up and down so that thge crystals do not posses any net dipole moment. |
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| 1145. |
A solid with high electrical and thermal conductivity from the following isA. `Si`B. `Li`C. `NaCl`D. `ICl` |
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Answer» Correct Answer - 2 Only metallic solids can have high electrical and thermal conductively .`Si` is a covalent solid ,`Li` is a metallic soilds.`NaCl` is an ionic solids whilst ice is a molecular solids. |
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| 1146. |
A solid with high electrical and thermal conductivity from the following isA. SiB. LiC. NaClD. Ice |
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Answer» Correct Answer - B Out of the given substances, only Li has high eletrical and thermal conducivity. |
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| 1147. |
What type of solid is generally characterized by having low melting point and low electrical conductivity?A. CovalentB. IonicC. MetallicD. Molecular |
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Answer» Correct Answer - D Molecular crystals are soft and have low m. pts. |
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| 1148. |
Name the parameters that characterized a unit cell. |
| Answer» A unit cell is characterised by two types of parameters. These are : (a, b, c) which may or may not be mutually perpendicular and angles between the edges `(alpha, beta and gamma)`. | |
| 1149. |
In a CPS (close packed structure) of mixed oxides, it is found that lattice has `O^(2-)` (oxide ions), and one half of octahedral voids are occupied by trivalent cations `(A^(3+))` and one-eight of tetrahedral voids are occupied by divalent cation `(B^(2+))`. Derive formula of the mixed oxide. |
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Answer» Number of octahedral voids ion in lattice = 1 Hence, Number of trivalent cations `(A^(3+)) = 1 xx (1)/(2) = (1)/(2)` Number of tetrahedral voids per ion in lattice = 2 Hence, Number of divalent cations `(B^(2+)) = 2 xx (1)/(8) = (1)/(4)` Thus, formula is `A_(1//2)O " or " A_(2)BO_(4)` |
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| 1150. |
If the radius of ` Mg^(2+)` ions, ` Cs^(+) " ions" , S^(2-)` ions and ` Cl^(-)` are 0.65 Å , 1. 69 Å , 1.84 Å and 1.81 Å respectively , calculate the coordination number of the cation in the crystals of MgS, MgO and CsCl. |
| Answer» Correct Answer - 6, octahedral | |