Table of Contents
- 1 What is the packing fraction for diamond?
- 2 What is meant by packing fraction of atoms?
- 3 Which has the highest packing fraction?
- 4 Why do you think a diamond is so hard and graphite is so soft?
- 5 Why does a diamond have a low packing fraction?
- 6 Why are the bonds in Diamond stronger than in silicon or germanium?
What is the packing fraction for diamond?
As we consider that diamond is having cubic structure and we know that the packing fraction for ccp and hcp is 0.74.
Which of the following has the lowest packing fraction?
Explanation: The least packing efficiency in the above options is a simple cube with an efficiency of 52 \%.
Is a diamond unit cell close packed?
The diamond structure is a very common form. This structure is based on the cubic close packed structure with 4 additional atoms (pictured as green balls) in holes within the structure. The form of carbon in diamonds has this structure. It is also the structure of crystalline silicon.
What is meant by packing fraction of atoms?
In crystallography, atomic packing factor (APF), packing efficiency, or packing fraction is the fraction of volume in a crystal structure that is occupied by constituent particles. It is a dimensionless quantity and always less than unity.
What is the efficiency of diamond?
The largest diamond he produced was 0.15 mm (0.0059 in) across; it was too small and visually imperfect for jewelry, but usable in industrial abrasives.
How do you solve packing fractions?
The fraction of total space that is filled with the inherent constituent particles of a particular cell or structure is called the packing fraction. It can be obtained by dividing the total volume occupied by constituent particles by the cell’s total volume.
Which has the highest packing fraction?
Detailed Solution
| Structure | Atomic packing factor |
|---|---|
| HCP | 0.74 |
| FCC | 0.74 |
| Diamond cubic | 0.34 |
| SC | 0.52 |
Which of the following has highest packing fraction?
Hexagonal close−packed lattice has the highest packing efficiency of 74\%.
Why is a diamond hard?
Diamonds are made of carbon so they form as carbon atoms under a high temperature and pressure; they bond together to start growing crystals. That’s why a diamond is such a hard material because you have each carbon atom participating in four of these very strong covalent bonds that form between carbon atoms.
Why do you think a diamond is so hard and graphite is so soft?
The carbon atoms in graphite appear to bond with weaker intermolecular forces, allowing the layers to move over one another. The weak intermolecular forces are known as the weak Van der Waals forces. Therefore, diamond is hard but graphite is soft and slippery even though both have carbon present in them.
Which of the following structures have the highest packing factor?
What is the value of packing fraction of FCC?
74.04 \%
The highest packing fraction possible is 74.04 \% and this is for the FCC lattice.
Why does a diamond have a low packing fraction?
In the diamond structure, each diamond uses its 4 valence electrons (sp3 hybridization) to form 4 bonds in a tetrahedral geometry. This low coordination number is responsible for the low packing fraction. In some other fcc structures (gold, copper, silver), all atoms have 12 neighbours, so a much higher packing fraction.
How much lower should a diamond price be than the price?
Emerald cut diamonds – should be 19-27\% lower than the prices mentioned in the above index. Pear cut diamonds – should be 15-22\% lower than the prices mentioned in the above index. Marquise cut diamonds – should 23-32\% lower than the prices mentioned in the above index.
What is the most efficient packing geometry for hard spheres?
Considering a system of hard spheres of a single size (with the caveat that atoms are not hard spheres), the most efficient packing geometries correspond to a hexagonal close packed (HCP) crystal structure or a face-centered cubic crystal structure (FCC). Both structures yield a 74\% packing fraction and consist of triangular planes.
Why are the bonds in Diamond stronger than in silicon or germanium?
The bonds in diamond are stronger than in silicon or germanium because atomic orbitals tend to be smaller higher up on the periodic table. Carbon atoms need to be closer together to bond with each other which also makes it difficult to pull them apart.