Question

Elements in the same column/group of the periodic table have similar chemical properties because their atoms have the same_________.

• A. number of protons.
• B. number electrons.
• C. number of valence electrons.
• D. atomic mass.

Answer 1

Answer: (B)

-number of valence electrons

The elements of same group have similar chemical properties because they have same number of valence electrons. For eg: Li has $1$ valence electron and so does $NA,K$ and $Cs$. Hence they have similar properties.