Page 1
Numerical
unit cell edge length of . The radius of sodium atom is
__________ (Nearest integer)
JEE Main 2023 (Online) 13th April Evening Shift
Q.1. Sodium metal crystallizes in a body centred cubic lattice with
Q.2. An atomic substance A of molar mass 12 g mol
-1
has a cubic
crystal structure with edge length of 300 pm. The no. of atoms
present in one unit cell of A is ____________. (Nearest integer)
JEE Main 2023 (Online) 6th April Evening Shift
Cubic, tetragonal, orthorhombic, hexagonal, rhombohedral,
monoclinic, triclinic
Q.4. A metal M crystallizes into two lattices :- face centred cubic
(fcc) and body centred cubic (bcc) with unit cell edge length
of 2.0 and 2.5A
o
respectively. The ratio of densities of lattices fcc to
bcc for the metal M is ____________. (Nearest integer)
JEE Main 2023 (Online) 11th April Morning Shift
Given the density of A is
Q.3. Number of crystal systems from the following where body
centred unit cell can be found, is ____________.
Page 2
Numerical
unit cell edge length of . The radius of sodium atom is
__________ (Nearest integer)
JEE Main 2023 (Online) 13th April Evening Shift
Q.1. Sodium metal crystallizes in a body centred cubic lattice with
Q.2. An atomic substance A of molar mass 12 g mol
-1
has a cubic
crystal structure with edge length of 300 pm. The no. of atoms
present in one unit cell of A is ____________. (Nearest integer)
JEE Main 2023 (Online) 6th April Evening Shift
Cubic, tetragonal, orthorhombic, hexagonal, rhombohedral,
monoclinic, triclinic
Q.4. A metal M crystallizes into two lattices :- face centred cubic
(fcc) and body centred cubic (bcc) with unit cell edge length
of 2.0 and 2.5A
o
respectively. The ratio of densities of lattices fcc to
bcc for the metal M is ____________. (Nearest integer)
JEE Main 2023 (Online) 11th April Morning Shift
Given the density of A is
Q.3. Number of crystal systems from the following where body
centred unit cell can be found, is ____________.
cell is __________. (Nearest integer)
Given: Molar mass of Fe and O is 56 and 16 g mol
-1
respectively.
JEE Main 2023 (Online) 30th January Evening Shift
Q.6. A metal M forms hexagonal close-packed structure. The total
number of voids in 0.02 mol of it is _________ × 1021 (Nearest
integer).
JEE Main 2023 (Online) 29th January Evening Shift
Answer key & Explanation
1. Ans. Correct answer is 17
Explanation
In a body-centered cubic (BCC) lattice, the relationship between
the edge length (a) and the atomic radius (r) is given by:
Given the unit cell edge length (a) of sodium metal as 4 Å:
JE
.5. Iron oxide FeO, crystallises in a cubic lattice with a unit cell
edge length of 5.0 Å. If density of the FeO in the crystal
is 4.0 g cm-3, then the number of FeO units present per unit
E Main 2023 (Online) 1st February Evening Shift
Q
Page 3
Numerical
unit cell edge length of . The radius of sodium atom is
__________ (Nearest integer)
JEE Main 2023 (Online) 13th April Evening Shift
Q.1. Sodium metal crystallizes in a body centred cubic lattice with
Q.2. An atomic substance A of molar mass 12 g mol
-1
has a cubic
crystal structure with edge length of 300 pm. The no. of atoms
present in one unit cell of A is ____________. (Nearest integer)
JEE Main 2023 (Online) 6th April Evening Shift
Cubic, tetragonal, orthorhombic, hexagonal, rhombohedral,
monoclinic, triclinic
Q.4. A metal M crystallizes into two lattices :- face centred cubic
(fcc) and body centred cubic (bcc) with unit cell edge length
of 2.0 and 2.5A
o
respectively. The ratio of densities of lattices fcc to
bcc for the metal M is ____________. (Nearest integer)
JEE Main 2023 (Online) 11th April Morning Shift
Given the density of A is
Q.3. Number of crystal systems from the following where body
centred unit cell can be found, is ____________.
cell is __________. (Nearest integer)
Given: Molar mass of Fe and O is 56 and 16 g mol
-1
respectively.
JEE Main 2023 (Online) 30th January Evening Shift
Q.6. A metal M forms hexagonal close-packed structure. The total
number of voids in 0.02 mol of it is _________ × 1021 (Nearest
integer).
JEE Main 2023 (Online) 29th January Evening Shift
Answer key & Explanation
1. Ans. Correct answer is 17
Explanation
In a body-centered cubic (BCC) lattice, the relationship between
the edge length (a) and the atomic radius (r) is given by:
Given the unit cell edge length (a) of sodium metal as 4 Å:
JE
.5. Iron oxide FeO, crystallises in a cubic lattice with a unit cell
edge length of 5.0 Å. If density of the FeO in the crystal
is 4.0 g cm-3, then the number of FeO units present per unit
E Main 2023 (Online) 1st February Evening Shift
Q
We can now solve for the radius (r) of the sodium atom:
Now, we can approximate the numerical value:
2. Ans. Correct answer is 4
Explanation
Given:
Page 4
Numerical
unit cell edge length of . The radius of sodium atom is
__________ (Nearest integer)
JEE Main 2023 (Online) 13th April Evening Shift
Q.1. Sodium metal crystallizes in a body centred cubic lattice with
Q.2. An atomic substance A of molar mass 12 g mol
-1
has a cubic
crystal structure with edge length of 300 pm. The no. of atoms
present in one unit cell of A is ____________. (Nearest integer)
JEE Main 2023 (Online) 6th April Evening Shift
Cubic, tetragonal, orthorhombic, hexagonal, rhombohedral,
monoclinic, triclinic
Q.4. A metal M crystallizes into two lattices :- face centred cubic
(fcc) and body centred cubic (bcc) with unit cell edge length
of 2.0 and 2.5A
o
respectively. The ratio of densities of lattices fcc to
bcc for the metal M is ____________. (Nearest integer)
JEE Main 2023 (Online) 11th April Morning Shift
Given the density of A is
Q.3. Number of crystal systems from the following where body
centred unit cell can be found, is ____________.
cell is __________. (Nearest integer)
Given: Molar mass of Fe and O is 56 and 16 g mol
-1
respectively.
JEE Main 2023 (Online) 30th January Evening Shift
Q.6. A metal M forms hexagonal close-packed structure. The total
number of voids in 0.02 mol of it is _________ × 1021 (Nearest
integer).
JEE Main 2023 (Online) 29th January Evening Shift
Answer key & Explanation
1. Ans. Correct answer is 17
Explanation
In a body-centered cubic (BCC) lattice, the relationship between
the edge length (a) and the atomic radius (r) is given by:
Given the unit cell edge length (a) of sodium metal as 4 Å:
JE
.5. Iron oxide FeO, crystallises in a cubic lattice with a unit cell
edge length of 5.0 Å. If density of the FeO in the crystal
is 4.0 g cm-3, then the number of FeO units present per unit
E Main 2023 (Online) 1st February Evening Shift
Q
We can now solve for the radius (r) of the sodium atom:
Now, we can approximate the numerical value:
2. Ans. Correct answer is 4
Explanation
Given:
Avogadro's number
First, calculate the volume of the unit cell
Next, calculate the mass of the unit cell using the given density.
Density is mass over volume, so mass
Then, calculate the number of moles in one unit cell. The molar
mass is mass over number of moles, so
Finally, calculate the number of atoms in one unit cell. The
Avogadro constant is the number of atoms per mole,
Rounding to the nearest integer, we get 4 atoms. So, there are 4
atoms present in one unit cell of substance A
3. Ans. Correct answer is 3
4. Ans. Correct answer is 4
Explanation
Page 5
Numerical
unit cell edge length of . The radius of sodium atom is
__________ (Nearest integer)
JEE Main 2023 (Online) 13th April Evening Shift
Q.1. Sodium metal crystallizes in a body centred cubic lattice with
Q.2. An atomic substance A of molar mass 12 g mol
-1
has a cubic
crystal structure with edge length of 300 pm. The no. of atoms
present in one unit cell of A is ____________. (Nearest integer)
JEE Main 2023 (Online) 6th April Evening Shift
Cubic, tetragonal, orthorhombic, hexagonal, rhombohedral,
monoclinic, triclinic
Q.4. A metal M crystallizes into two lattices :- face centred cubic
(fcc) and body centred cubic (bcc) with unit cell edge length
of 2.0 and 2.5A
o
respectively. The ratio of densities of lattices fcc to
bcc for the metal M is ____________. (Nearest integer)
JEE Main 2023 (Online) 11th April Morning Shift
Given the density of A is
Q.3. Number of crystal systems from the following where body
centred unit cell can be found, is ____________.
cell is __________. (Nearest integer)
Given: Molar mass of Fe and O is 56 and 16 g mol
-1
respectively.
JEE Main 2023 (Online) 30th January Evening Shift
Q.6. A metal M forms hexagonal close-packed structure. The total
number of voids in 0.02 mol of it is _________ × 1021 (Nearest
integer).
JEE Main 2023 (Online) 29th January Evening Shift
Answer key & Explanation
1. Ans. Correct answer is 17
Explanation
In a body-centered cubic (BCC) lattice, the relationship between
the edge length (a) and the atomic radius (r) is given by:
Given the unit cell edge length (a) of sodium metal as 4 Å:
JE
.5. Iron oxide FeO, crystallises in a cubic lattice with a unit cell
edge length of 5.0 Å. If density of the FeO in the crystal
is 4.0 g cm-3, then the number of FeO units present per unit
E Main 2023 (Online) 1st February Evening Shift
Q
We can now solve for the radius (r) of the sodium atom:
Now, we can approximate the numerical value:
2. Ans. Correct answer is 4
Explanation
Given:
Avogadro's number
First, calculate the volume of the unit cell
Next, calculate the mass of the unit cell using the given density.
Density is mass over volume, so mass
Then, calculate the number of moles in one unit cell. The molar
mass is mass over number of moles, so
Finally, calculate the number of atoms in one unit cell. The
Avogadro constant is the number of atoms per mole,
Rounding to the nearest integer, we get 4 atoms. So, there are 4
atoms present in one unit cell of substance A
3. Ans. Correct answer is 3
4. Ans. Correct answer is 4
Explanation
5. Ans. Correct answer is 4
Explanation
6. Ans. Correct answer is 36
Explanation
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