Question

Which two elements are in the same period?A. hydrogen (H) and neon (Ne)B. tin (Sn) and antimony (Sb)C. fluorine (F) and chlorine (Cl)D. arsenic (As) and antimony (Sb)

Answer 1

Answer:

C. fluorine (F) and chlorine (Cl)

D. arsenic (As) and antimony (Sb)

Explanation:

In the periodic table , all the elements are arranged according to the atomic number ,

and the elements are placed in groups and periods ,

The elements with similar chemical and physical properties are placed in a common group .

The elements present in the same group have the same number of valence electrons in the valence shell  .

Hence , from the given options ,

fluorine (F) and chlorine (Cl)  belongs to group 17 with 7 valence electrons in the outermost shell .

arsenic (As) and antimony (Sb) belong to group 15 with 3 valence electrons in the outermost shell .