Question

A synthetic element has $116$ protons in its nucleus. Find a place in the modern table and element it, may resemble in properties from the following:

• A. ${}_{55}{}^{}\mathrm{Cs}$
• B. ${}_{84}{}^{}\mathrm{Po}$
• C. ${}_{86}\mathrm{Ra}$
• D. Element with $115$ protons

Answer 1

The correct option is B

${}_{84}{}^{}\mathrm{Po}$

Explanation for correct option:

(B) ${}_{84}{}^{}\mathrm{Po}$

• The proton number is nothing but the atomic number of the element.
• The last element of the periodic table is oganesson with the atomic number of $118$ which is placed in the seventh period and the eighteenth group which is the noble gas family.
• The given element is two units lesser than the last element which means it should be placed under the sixteenth group which is the chalcogen family.
• The members of the chalcogen family are oxygen, sulphur, selenium, and Polonium with atomic number $84$. Hence, the given element will have similar properties to polonium.

Explanation for incorrect option:

(A) ${}_{55}{}^{}\mathrm{Cs}$

• Caesium belongs to alkaline earth metals which do not show similar properties to the given element.
• This is an incorrect option.

(C) ${}_{86}\mathrm{Ra}$

• Radon belongs to the noble gas group-$18$ which does not show similar properties to the given element.
• this is an incorrect option.

(D) Element with $115$ protons

• Element with $115$ protons belongs to the nitrogen family which does not show similar properties to the given element
• this is an incorrect option.

Hence, the correct option is (B) ${}_{84}{}^{}\mathrm{Po}$.