Question

The similarity in the properties of a Group of elements is because they have the same___________. (electronic configurations/number of outermost shell electrons/atomic numbers)

Answer 1

• Modern periodic table is the arrangement of elements on the basis of increasing atomic number in 7 horizontal rows and 18 vertical columns. Horizontal rows are termed as Periods while the vertical columns are termed as Groups.
• Valence electrons of any element are defined as the number of electrons present in the outermost shell of any element.
• Valence electrons in any element can be predicted by their Group number because the elements present in the same vertical column have the same number of electrons present in the outermost shell.
• Example: Elements in Group 1 have 1 valence electron and elements in Group 2 have 2 valence electrons.
• Thus, the similarity in the properties of a Group of elements is because they have the same number of outermost shell electrons.