Question

Recently discovered element with atomic number $115$ is:
(A)- ${\text{Uun}}$
(B)- ${\text{Uub}}$
(C)- ${\text{Uup}}$
(D)- ${\text{Uus}}$

Answer 1

Hint: It comes under the category of post transition metal, which are situated in between the transition series and p-block i.e. in the left side of post transition metals transition metals are present & in the right side of this element metalloids of p-block elements are present.

Complete Solution :
Element with atomic number $115$ was discovered on 10th September, 2013. It is a synthesized element, which was prepared by the scientist as a heavy element.
-Name of the element is Ununpentium which is denoted as ‘${\text{Uup}}$’, where Un stands for 1 & pent stands for 5 i.e. ${\text{1 = Un}}$ & ${\text{5 = Pent}}$.
-${\text{Uup}}$ also denoted as ${}_{{\text{288}}}^{{\text{115}}}{\text{Uup}}$, where upper term is known as atomic number & lower term is known as atomic mass.
So, the correct answer is “Option C”.

Additional information : Also we know that, Atomic Number of an atom = no. of electrons or no. of protons and Atomic Mass of an atom = no. of protons + no. of neutrons present in the nucleus.
-So that, no. of protons = no. of electrons = 115
And no. of neutrons = $288 - 115 = 173$.
-Electronic configuration of ${\text{Uup}}$ is $\left[ {{\text{Rn}}} \right]{\text{5}}{{\text{f}}^{{\text{14}}}}{\text{6}}{{\text{d}}^{{\text{10}}}}{\text{7}}{{\text{s}}^{\text{2}}}{\text{7}}{{\text{p}}^{\text{3}}}$, where Rn stands for radon gas which is a noble gas.

Note: Some of you may give the wrong answer to this question, because in periodic table one more element with atomic number 115 was already present, whose name is Moscovium which was discovered in 2003. But in this question they are asking for recently discovered, so the answer will be ${\text{Uup}}$.