Question

The electronic configuration of $U^{3+}$ ion is:

Answer 1

In order to find out the electronic configuration of the ion given in the question we must know the atomic number of Uranium and also that it belongs to the f-block (inner transition elements) of the Modern periodic table. Then we need to find the electronic configuration of Uranium followed by its configuration in +3 state to get the answer.

Complete answer:
Few properties of Uranium are as under-
(a)Uranium is a radioactive element. It belongs to the actinide series of the periodic table. It was first discovered by a German chemist Martin Heinrich Klaproth.
(b) The atomic number of Uranium is 92. Mass of Uranium is 238.028.There are several artificially synthesized isotopes of Uranium also present.
(c)It is the heaviest naturally occurring element in the earth crust. Also it is found in water and rocks. It is the 51st abundant element in the earth crust.
(d)It is used to produce electricity in nuclear power plants. It is also used in Nuclear weapons and nuclear submarines.
(e)It is silver in color and oxidizes easily in air. It is a little softer than steel.
The ground state electronic configuration of Uranium is- $[Rn]5{f^3}6{d^1}7{s^2}$
Now we have to find electronic configuration in +3 oxidation state.+3 oxidation state means loss of 3 electrons from the outermost shell and hence it s and p electrons and become- $[Rn]5{f^3}$

Note:
The nucleus of Uranium is Radioactive and decays by alpha particles and hence the exposure to Uranium is not that dangerous as compared to exposure to other radioactive elements. However long exposure of Uranium can lead to several health care effects such as cancer of the bone or the liver.