Properties of Crystals

Anisotropy is defined as:

• Anisotropy is the property of being isotropic.
• Anisotropy is the property of being independent of direction.
• Anisotropy is the property of being uniform in all directions.
• Anisotropy is the property of being directionally dependent.

Graphite is anisotropic in nature because:

• allow passage of current parallel to layers not perpendicular to layers

• Graphite has a uniform structure in all directions.
• Graphite is a synthetic material.
• Graphite is a conductor of electricity in all directions.

crystal growth is defined as:

• The process by which a crystal is formed from a saturated solution.
• The process by which a crystal is formed from a diluted solution.
• The process by which a crystal is formed from a solid material.
• The process by which a crystal is formed from a supersaturated solution or a melt under specific conditions of temperature, pressure, and chemical environment.

The plane of symmetry of crystal is:

• A plane of symmetry divides a crystal into two unequal halves.
• A plane of symmetry divides a crystal into three equal parts.
• A plane of symmetry divides a crystal into two parts that are not mirror images of each other.
• A plane of symmetry divides a crystal into two equal halves that are mirror images of each other.

The axis of symmetry of crystal is:

• A line that passes through the corners of the crystal.

• A physical line that can be seen on the surface of the crystal.

• A line that divides the crystal into three equal parts.

• The imaginary line that passes through the center of the crystal at which crystal can be ratated at 360^o

The center of symmetry of crystal:

• Located on the surface of the crystal.

• The point within the crystal where the arrangement of atoms or molecules is asymmetrical.

• The point within the crystal where the arrangement of atoms or molecules is symmetrical in all directions.

• A random point within the crystal.

Crystalline solids have sharp melting point due to:

• Amorphous structure of the solid
• Irregular arrangement of particles in a crystal lattice
• High density of the solid
• Regular arrangement of particles in a crystal lattice

Allotropy takes place in:

• elements
• mixtures
• ions
• compounds

which is not crystalline allotrope of carbon:

• diamond
• graphite
• fullerene
• charcoal

Transition temperature is defined as:

• The temperature at which a substance does not undergo any change.
• The temperature at which a substance changes its color.
• The temperature at which a substance undergoes a phase transition.
• The temperature at which a substance evaporates completely.