Question

Reference to the long form of the periodic table fills in the blanks with appropriate words.

The______elements are accommodated in the middle of the periodic table.

Answer 1

Modern periodic table:

• The modern periodic table is an arrangement of all the elements known in accordance with their increasing atomic number and recurring chemical properties.
• It is a tabular display of 118 chemical elements which consists of horizontal rows called periods and vertical columns are called groups.
• All elements in a group have the same number of valance electrons, and in period elements have the same number of electron shells.

Transition elements:

• Elements that correspond to the d-block of the modern periodic table (which consists of groups 3-12) is considered to be transition element.
• Transition metals are placed between s−block and p−block elements in the periodic table.
• They exhibit transitional behaviour between s block and p block elements so they are called transition elements.
• The elements mercury, cadmium, and zinc are not considered transition elements because of their electronic configurations.

Hence, the transition elements are accommodated in the middle of the periodic table.