How will you distinguish between the following pair of term? Tetrahedral void and octahedral void?

Differences between tetrahedral void and octahedral void are as follows: Tetrahedral void Octahedral void Tetrahedral void is a simple triangular void in a crystal and is surrounded by four spheres arranged tetrahedrally around it. Octahedral void is a double triangular void with one triangle vertex upwards and the other triangle vertex downwards and is surrounded by six spheres. Radius r of tetrahedral void = 0 . 225 × R (Radius of sphere in packing) Shape of tetrahedral void Radius r of octahedral void = 0 . 414 × R (Radius of sphere in packing) Shape of octahedral void.

How will you distinguish between the following pair of term? Hexagonal close-packing and cubic close packing?

Differences between Hexagonal close packing and cubic close packing are as follows: Hexagonal close packing Cubic close packing By this type of packing tetrahedral voids are covered by spheres. By this type of packing octahedral voids are covered by spheres. Here the spheres in every third or alternate are vertically aligned i.e., the third layer is directly above the first, the fourth above the second layer and so on. Here the spheres in every fourth layer will be vertically aligned i.e., the fourth layer is directly above the first and the fifth layer is above the second layer. This type of pattern is called AB-AB type. It is found in Mg and Zn . This type of pattern is called ABC-ABC type. It is found in Cu , Ag , etc.

What type of semiconductor is created when Ge is doped with In?

Silicon or germanium can also be doped with a group of 13 elements like B, Al or Ga which contains only three valence electrons. This type of semiconductor is called a p-type semiconductor. Here, Germanium is tetravalent and indium is trivalent. Thus, when Ge is doped with In, the semiconductor obtained is a p-type semiconductor.

In terms of band theory, what is difference between a conductor and a semiconductor? Explain.

In conductor, the valence band is partially filled (unpaired electrons) and it overlaps with a high energy unoccupied conduction band. These unpaired free electrons can easily flow under an applied electric field. In semiconductor, the valence band is filled (paired electrons) and there is a small gap between the valence band and the next higher conduction band. Some electrons can jump from the valence band to the conduction band and conduct electricity. The semiconductors have properties that are between both conductors and insulators. They are formed by doping which means by adding small amounts of different elements that increase the charge carriers.

Copper crystallizes in fcc lattice with edge length 3 . 61 × 10 - 8 cm . Show that the calculated density is in agreement with its measured value of 8 . 92 g / cm 3 .

Given, Edge length a = 3.61 × 10 - 8 c m . The lattice is of FCC type. Therefore, the number of atoms per unit cell, Z = 4 Atomic mass, M = 63.5 g m o l - 1 We also know that, N A = 6.022 × 10 23 Applying the relation: d = Z M a 3 N A = 4 × 63 .5 g mol - 1 3 .61 × 10 - 8 cm 3 × 6 .022 × 10 23 mol - 1 = 8 . 97 g cm - 3 Hence, the calculated density 8.97 g c m - 3 is in agreement with its measured value which is 8.92 g cm - 3 .

Define the following with suitable examples: Antiferromagnetism.

Antiferromagnetism is the presence of magnetic domains that are aligned in opposite directions in magnetic materials. These opposite magnetic domains have equal magnetic moments which are cancelled out (since they are in opposite directions). This makes the net moment of the material zero. This type of materials is known as antiferromagnetic materials. <img alt="Key Difference - Ferromagnetism vs Antiferromagnetism" data-jpibfi-post-excerpt="" data-jpibfi-post-title="Difference Between Ferromagnetism and Antiferromagnetism" data-jpibfi-post-url="https://www.differencebetween.com/difference-between-ferromagnetism-and-vs-antiferromagnetism/" data-jpibfi-src="https://i0.wp.com/www.differencebetween.com/wp-content/uploads/2018/04/Difference-Between-Ferromagnetism-and-Antiferromagnetism_Figure-1-e1522909061802.png?resize=576%2C219&ssl=1" height="219" sizes="(max-width: 576px) 100vw, 576px" src="https://i0.wp.com/www.differencebetween.com/wp-content/uploads/2018/04/Difference-Between-Ferromagnetism-and-Antiferromagnetism_Figure-1-e1522909061802.png?resize=576%2C219&ssl=1" srcset="https://i0.wp.com/www.differencebetween.com/wp-content/uploads/2018/04/Difference-Between-Ferromagnetism-and-Antiferromagnetism_Figure-1-e1522909061802.png?w=410&ssl=1 410w, https://i0.wp.com/www.differencebetween.com/wp-content/uploads/2018/04/Difference-Between-Ferromagnetism-and-Antiferromagnetism_Figure-1-e1522909061802.png?resize=300%2C114&ssl=1 300w" title="Difference Between Ferromagnetism and Antiferromagnetism 2" width="576" /> Common examples of antiferromagnetic materials can be found from transition metal oxides such as manganese oxide ( MnO ).

Define the following with suitable examples: F-centres.

F-centres: If the number of missing anions is more than cations, to maintain electrical neutrality some electrons are trapped at anionic vacancies. Because of these extra electrons, the electrical and optical properties of the compound get modified. So these locations are also known as colour centres. ZnO , white in colour at room temperature. On heating, some oxygen ions get released in the form of oxygen and electrons released are trapped at their locations. Because of this, it becomes yellow in colour.

E M B I B E

EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY>Chapter -1 - The Solid State>Haryana Board-2019>Q 9

EASY

12th Haryana Board

IMPORTANT

Earn 100

How many lattice points are there in one unit cell of body-centered lattice?

Chapter-Wise 3D Chemistry Videos from Embibe Experts EMBIBE CHAPTER WISE PREVIOUS YEAR PAPERS FOR CHEMISTRY

05 min 06 sec

The Face-centered Cubic Unit Cell

The video discusses the parameters involved in defining a Face centered cubic unit cell. It describes the relationship between the edge length of the cube an...

05 min 37 sec

Body-centred Cubic Unit Cell

The video describes the relationship between the edge length of the cube and the radius of the atom present in the BCC unit cell and the contact line for the...

05 min 29 sec

Hexagonal Close Packing in 2D and 3D

When the rows of spheres are stacked over each other, a 2D closed packed structure is produced. Let’s see how the stacking is done to produce a hexagonal clo...

Learn and Prepare for any exam you want !

|

|

|

|

|

|

|

|