Question

What is the Periodic Table?

Answer 1

Periodic table:

• “The physical and chemical properties of the elements are periodic functions of their atomic numbers”-This was proposed by Henry Moseley.
• The horizontal rows are called periods while the vertical columns are known as groups.
• “According to the recommendation of the International Union of Pure and Applied Chemistry (IUPAC), the groups are numbered from $1\mathrm{to}18$ replacing the older notation of groups $\mathrm{IA}\dots \mathrm{VIIA},\mathrm{VIII},\mathrm{IB}\dots \mathrm{VIIB},\mathrm{and}0$”.
• There is a total of seven periods. The period number is the highest principal quantum number (n) of the elements in the period.
• Group-$1$ is identified as Alkali metals while Group-$2$ is Alkaline earth metals.
• Group $17$ is known as the Halogen family while the elements of Group-$18$ are Noble gases.
• $d$and $f$ block elements are transition and inner transition elements respectively.