Explain crystalline solids and amorphous solids.

Answer : i. Crystalline solids: a. A crystalline solid usually consists of a large number of small crystals, each of them having a definite characteristic geometrical shape. These tiny crystals are called unit cells. b. A unit cell is a […]

Give the classification of solids.

 Answer:  Solids are classified as crystalline and amorphous on the basis of the presence or absence of orderly arrangement of their constituent particles (atoms, ions or molecules). i. Crystalline solids: A crystalline solid is a homogeneous solid in which the […]

Give characteristics of solid state.

The solid state is characterized by the following properties: i. Solids have definite mass, volume, shape and density. Usually, the density of solid state is greater than the density of liquid and gaseous state. Water and mercury are exceptions. The […]

Define a solid. Under what conditions does a substance exist in solid state?

Answer:                 Matter can exist in three states namely, solid, liquid and gas. Under a given set of conditions of temperature and pressure, the most stable state of a substance depends upon the […]

Briefly explain why electronic configurations of lanthanoids are not known with certainty.

In the lanthanoids, 4f and 5d subshells are very close in energy. The outermost 6s-orbital remains filled with two electrons (6s2) . The electrons can easily jump from 4f to 5d or vice-versa. Further, irregularities in electronic configurations are also […]

What are lanthanoids? Explain the position of lanthanoids in the periodic table.

The series involving the filling of 4f-orbitals following lanthanum La (Z = 57) is called lanthanoid series. The elements present in this series are called lanthanoids. There are fourteen elements in this series starting with cerium, Ce(Z = 58) and […]

Explain the meaning of inner transition series.

i. The last electron in the f-block elements enters into (n-2) f-orbitals, i.e., inner to the penultimate energy level and they form a transition series within the transition series (d-block elements). Hence, the f-block elements are known as inner transition […]