100+ Periodic Classification of Elements Questions and Answers - 1

Question: 1

Mention the uses of Mendeleev's periodic table?

Some vacant places were found in this table. This provide a clue for the discovery of new elements.

Mendeleev predicted their occurrence on earth and called these elements Eka-aluminium and Eka-Silicon.

Later they were discovered and named as Gallium and Germanium.

Question: 2

State Mendeleev's periodic law?

The properties of elements are periodic functions of their atomic masses.

Question: 3

Define atomic radius?

Atomic radius is defined as the distance between the centre of nucleus of the atom to the outer most shell of electrons.

Question: 4

What is law of triad?

A similar element exists in groups of three elements named triads. The atomic mass of the middle member is the arithmetic mean of the atomic masses of the other members of the triad. This is known as Law of triad.

Question: 5

State the modern periodic table?

The physical and chemical properties of elements are the periodic functions of their atomic numbers.