Tag: introduction to solids

Questions Related to introduction to solids

What makes the molecular crystals solid at low temperature?

  1. Sharing of electrons.

  2. Transfer of electrons.

  3. Vander Waal's force arising out of polarisation.

  4. All of the above.


Correct Option: C
Explanation:

Vander Waal's forces make the molecular crystals, solids at low temperature.


Its properties are dictated by the weak nature of these intermolecular forces.

A molecular crystalline solid:

  1. is very hard

  2. is volatile

  3. has a high melting point

  4. is a good conductor


Correct Option: B
Explanation:

Molecular solid is a solid in which the constituent particles are atoms or molecules which are held together by weak intermolecular forces i.e. van der Waals forces. Due to weak forces, they are volatile.

Wax is an example of:

  1. ionic crystal

  2. covalent crystal

  3. molecular crystal

  4. metallic crystal


Correct Option: C

$KCl(s)$ is:

  1. An ionic substance

  2. A polar covalent substance

  3. A nonpolar covalent substance

  4. An amorphous substance

  5. A metallic network


Correct Option: A
Explanation:

Potassium chloride KCl is a metal halide salt composed of potassium and chloride. It is odorless and has a white or colorless vitreous crystal appearance. The solid dissolves readily in water and its solutions have a salt-like taste.


In aqueous solution,

$KCl\longrightarrow { K }^{ + }+{ Cl }^{ - }$

It is an ionic substance in solid state.

This allows many solids to conduct electricity :

  1. Hydrogen bonding

  2. Ionic bonding

  3. Metallic bonding

  4. Nonpolar covalent bonding

  5. Polar covalent bonding


Correct Option: C
Explanation:


Metallic bonding is the strong attraction between closely packed positive metal ions and a sea of delocalised electrons. The delocalised electrons are able to move through the metallic structure. When a potential difference  is applied, they will move together, allowing an electric current to flow through the metal.

The nature of bonds in compounds of C and Si is:

  1. ELectrovalent

  2. Covalent

  3. Metallic

  4. Covalent and electrovalent


Correct Option: B
Explanation:

Carbon and silicon are chemical elements with atomic number 6 and 14. they are nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. Option-B.

$I$. Metallic solids tend to be very brittle.

$II$. Metallic bonds are broken quite easily.

  1. Statement $I$ is true, Statement $II$ is true

  2. Statement $I$ is true, Statement $II$ is false

  3. Statement $I$ is false Statement $II$ is true

  4. Statement $I$ is false, Statement $II$ is false


Correct Option: D
Explanation:

Metallic solids are generally non-brittle or highly malleable and ductile. Also metallic bond is one of the strongest bonds. 

Therefore both statements are false.

Which of the following statements is true?

  1. Molecular crystals are very hard and incompressible

  2. Ionic crystals have very low volatility

  3. Metallic bond is directional and rigid

  4. Boron nitride has an ionic crystal structure


Correct Option: B
Explanation:

Ionic crystals have very low volatility. Generally, ionic solids are having ionic bonds between the constituent atoms. 

Ionic bonds are very strong bonds. So they are less volatile.

Iodine crystals are 

  1. Metallic solid

  2. Ionic solid

  3. Molecular solid

  4. Covalent solid


Correct Option: C

Which of the following solid is made up of ions?

  1. Sugar

  2. Common salt

  3. Polythene

  4. Wood


Correct Option: B