Question

Which of the following statements is correct?
A. All the transuranic elements are synthetic elements
B. Elements of the third group are called bridge elements
C. Element of $1{s^2}$ configuration is placed in $IIA$ group
D. Electronic configuration of elements in a group is the same.

Answer 1

Transuranic elements are the elements placed after uranium in the periodic table, and have very short life-spans.

Bridge elements show resemblance of properties with elements placed diagonally below them.

The element with configuration $1{s^2}$ is Helium, and as we know, electronic configuration indicates the order of filling of electrons in an atom.

Complete step by step answer:
Let us first examine the first statement and check its validity. Transuranic elements refer to elements which come after uranium in the periodic table, and most of them are radioactive. They do not occur naturally and are produced through nuclear reactors. Thus, option A is correct.
Bridge elements in the periodic table are those which show resemblance in characteristics with elements placed in the next period and group, that is their corresponding diagonal elements. This trend is shown by second period elements, and not the third group elements. Hence, option B is incorrect.
An electronic configuration of $1{s^2}$ means the element only has two electrons, and as we know, that would be the second element of the periodic table, Helium. Although it is the second element, it is placed in the eighteenth group as it is a noble gas. Hence, option C is incorrect.
Electronic configuration is the order in which electrons fill up in an atom. As all elements have different numbers of electrons, no two elements can have the same electronic configuration. Hence, option D is also incorrect.

So, the correct answer is Option A.

Note: Transuranic elements are produced by the process of nuclear fusion, where the nuclei of two atoms are fused together to form a heavier element. As they decay fast, their life-spans are very short, and are not found in nature. Note that while the second period elements are called bridge elements, their corresponding diagonal elements in the third period are known as the typical elements.