Classification ...

Mendeleev arranged elements in a periodic table in order of their increasing atomic weights in such a way that the elements with similar properties occupies

It is now recognized that the ‘Modern Periodic Law’ is essentially the consequence of

The first ionisation potential of Na is 5.1 eV. The value of electron gain enthalpy of Na⁺ will be

Mendeleev proposed that some of the elements were still undiscovered and, therefore, left several gaps in the table. He left the gap under aluminium and a gap under silicon, and called these elements Eka-Aluminium and Eka-Silicon. These were later discovered and named

Alkali metals belong to

Which of the following statements is true?

Complete the statement with suitable  word /(s)
Modern Periodic Law is stated as:
"Physical and chemical properties of different elements are periodic functions  of their ......... ?

Modern periodic law states that the periodic properties of elements are the periodic function of

The first, second and third ionisation energies of an atom are 737, 1451 and 7733 kJ mol^–1, respectively. The element can be

According to the recommendation of International Union of Pure and Applied Chemistry (IUPAC), the groups in the modern periodic table are numbered from