Advertisements
Advertisements
Question
Answer the following in brief.
How are the spheres arranged in first layer of simple cubic close-packed structures? How are the successive layers of spheres placed above this layer?
Solution
Simple cubic close-packed structures are obtained by stacking two-dimensional square close-packed layers.
So, the spheres in the first layer are placed adjacent to one another to form two dimensional square close packing (i.e., AAAA type arrangement). All the spheres of the successive layers are placed exactly above the spheres of the lower layers. This results in perfect horizontal and vertical alignment between the spheres of various layers.
APPEARS IN
RELATED QUESTIONS
Choose the most correct answer.
In crystal lattice formed by bcc unit cell, the void volume is _______.
Choose the most correct answer.
The coordination number of atoms in bcc crystal lattice is _______.
Choose the most correct answer.
A compound forms hcp structure. Number of octahedral and tetrahedral voids in 0.5 mole of substance is respectively _______.
Answer the following in one or two sentences.
Sketch a tetrahedral void.
How are tetrahedral and octahedral voids formed?
Third layer of spheres is added to second layer so as to form hcp or ccp structure. What is the difference between the addition of third layer to form these hexagonal close-packed structures?
An octahedral void is surrounded by ________.
A metal crystallizes in bcc lattice with edge length 4.48 Å. The radius of the metal atom is ___________ Å.
An element crystallises in a bee lattice with cell edge of 500 pm. The density of the element is 7.5 g cm-3. How many atoms are present in 300 g of metal?
The ratio of close-packed atoms to tetrahedral holes in cubic close packing is ____________.
A metallic element crystallises in simple cubic lattice. If edge length of the unit cell is 3Å, with density 8 g/cc, what is the number of unit cells in 100 g of the metal?
(Molar mass of metal = 108 g/mol)
Xenon crystallises in fcc lattice and the edge length of unit cell is 620 pm. What is the radius of Xe atom?
The coordination number of each sphere in bcc lattice is ____________.
In two dimensional AAAA type packing, the coordination number of each sphere is ____________.
In ABCABC type arrangement of spheres, the coordination number of any sphere is __________.
The atoms of element 'Y' form hexagonal close packing and the atoms of element X occupies `3/4` th portion of the number of tetrahedral voids. The formula of the compound formed by X and Y is ____________.
Zinc forms hcp structure. What is the number of octahedral voids formed in 0.2 mol of it?
A metallic element crystallizes in simple cubic lattice. If edge length of the unit cell is 3Å, with density 8 g/cc, what is the number of unit cells in 108 g of the metal?
(Molar mass of metal = 100 g/mol)
Percentages of free space in cubic close-packed structure and in the body-centered packed structure are respectively ______.
Which metal crystallises in a simple cubic structure?
The coordination number of cobalt in the complex [Co(en)2Br2]Cl2 is ______.
How much vacant space is present in hep crystal lattice?
Predict the type of cubic lattice of a solid element having edge length of 400 pm and density is 6.25 g/ml.
(Atomic mass of element = 60)
