Question

The atomic number of the element next to bromine (Atomic No. 35) in the same group is:
A) 43
B) 50
C) 56
D) 53

Answer 1

Hint: In the periodic table group is a column containing a number of chemical elements. There are 18 groups in the periodic table. The elements in the same group have the same chemical properties because of the same number of valence electrons.

Complete step by step answer:
-The electronic configuration of Bromine is $[\mathrm{Ar}] 3 \mathrm{d}^{10} 4 \mathrm{s}^{2} 4 \mathrm{p}^{5}$ with atomic number as 35.
-The valence shell electronic configuration of these electrons is $\mathrm{ns}^{2} \mathrm{np}^{5}$.
- Thus, there are 7 electrons in the outermost shell of these elements.
-Thus it belongs to the group 17.
-Group 17 is a special type of group. It is called a halogen group or halogen family group.
-They are called “halogens” because they give salts when they react with metals.
-The group 17 elements include fluorine(F), chlorine(Cl), bromine(Br), iodine(I) and astatine(At) from the top to the bottom.
- The atomic numbers of the elements in group-17 are fluorine (9), chlorine (17), bromine (35), iodine(53)and Astatine (85).
- Therefore the element which belongs to group-17 next to bromine (Atomic No. 35) in the same group is Iodine with atomic number 53.
-Iodine is added to common salt and is labelled as iodised salt. Deficiency of iodine causes a disease called goitre.
So, the correct answer is “Option D”.

Note: If we are supposed to find any element in the periodic table we should know the atomic number of that particular element. After knowing the atomic number we are supposed to write the electronic configuration of the element. By the electronic configuration we can easily find the position of the element in the periodic table.