Question

Why do periodic properties such as ionization enthalpy , electron gain enthalpy and electronegativity show a decreasing trend down the group but an increasing trend along a period?

Answer 1

Dear student,
The periodic properties show a decreasing trend down the group and increase across the period because of two major variations
1.Across the period the number of shells remain the same but atomic number increases
2.As we go down the group the number of shells get added with the increase in atomic number.