Question

Give the name and symbol of the following elements which occupy each of the following positions in the Mendeleev periodic table.

Period 1 Group 1a

Answer 1

Mendeleev periodic table:

• In Mendeleev, periodic table elements were arranged based on increasing atomic mass.
• During Mendeleev, only 63 elements were known so after studying the properties of elements he arranged them into vertical columns called groups, and horizontal rows are called periods.
• During the arrangement, there were seven periods and eight groups in Mendeleev's periodic table.

Name and symbol of the following elements:

Period 1 Group 1a: Hydrogen ($\mathrm{H}$)