Sign up now
to enroll in courses, follow best educators, interact with the community and track your progress.
Solid State I
559 plays

Amorphous and crystalline solids

Shaillee Kaushal is teaching live on Unacademy Plus

Shaillee Kaushal
Faculty in Chemistry with a teaching experience of 14 years. Specialised in teaching for boards and competitions.

Unacademy user
mam its contains physical chemistry only when u will add organic and inorganic part plzzz tell me mam.....
Sajid wasi
a year ago
thanx mam
Please give me a complete link of inorganic chemistry
mam please give pdf of important question
mam please add full courses soon

  2. In Solid State: Particles are closely packed .These are held together by strong intermolecular forces. There is only one type of motion(Vibrational motion) b virtue of which the particles move about fixed position arn cannot leave the solid surfac ERATION VER

  3. General characteristics: 1.Definite shape and volume: 2. High density and low compressibility: 3.Very slow diffusion 4. Vapour Pressure 5. Melting point

  4. Forms of solids: Solids are divided into two classes on t of haphazard and regular arrangement. e basi (i) Amorphous solids: Amorphous means shapeless nts is the arrangement of building constitu not regular but haphazard. they do not have characteristic shapes or geometrical forms Amorphous solids in many respects resemble liquids which flow very slowly at roonm temperature and regarded as supercooled liquids. Glass Rubber The cohesive forces holding the molecules together are so great that the material is rigid but there is no regularity of the structure Glass, rubber plastic etc. are examples

  5. >They do not have sharp melting point as glass when heated softens and then starts flowing without any abrupt change Glass is called a pseudo solid or a super cooled liquid. This can be illustrated by the fact that the glasses of windows of old buildings are thick at the bottom. This is because the glass melts slowly and the bottom is thickened So Amorphous solids are pseudo solids (false solids and lie in between solids and liquids)

  6. Crystalline solids The building constituents arrange themselves in regular manner throughout the entire three dimensional network The ordered arrangement extend over a large distance therefore the have long range ordeir. A crystalline solid consists of large number of units called crystals * A crystal is defined as a solid figure which has a definite geometrical shape, with flat faces and sharp edges. It has a sharp melting point i.e it changes abruptly into liquid state. Crystalline solid is a true solid Diamonds Table Salt

  7. Isotropy and Anisotropy Anisotropic_Substances, exhibiting directional differences in propeties are called anisotropic Crystalline solids are anisotropic magnitude of some of the physical properties of crystalline solids such as refractive index, coefficient of thermal expansion, electrical and thermal conductivities is different in different directions. For example, in the crystal of silver iodide (Agl), the co-efficient of thermal expansion is positive in one direction and negative in the other. The phenomenon of anistropy provides a strong evidence for the presence of ordered molecular arrangement in crystals