Question

Elements after atomic number $92$ are called
A. Lanthanide
B. Actinoids
C. Inner-transition elements
D. Transuranium elements

Answer 1

Hint: In the given question we have to find out what is the set of elements that are mentioned as they all belong to a specific group of elements. Now we can relate to the trend of the period by the help of the general trend of the series. Then we know that it would increase down the group so the one at the top is weakest.

Complete Answer:
- The given question is asked about the metallic character of the given elements. All these elements belong to the group $1$ of the modern periodic table and are considered generally most metallic among the entire series of elements in the world into existence.
- The transuranium elements (also known as transuranic elements) are the chemical elements with atomic numbers greater than $92$ , which is the atomic number of uranium. All of these elements are unstable and decay radioactively into other elements.
- The transuranium elements are the chemical elements with atomic numbers greater than 92 (the atomic number of uranium).

Hence, the correct option is D, Transuranium elements.

Note:
All the elements with higher atomic numbers have been first discovered in the laboratory, with neptunium and plutonium later also discovered in nature. They are all radioactive, with a half-life much shorter than the age of the Earth, so any primordial atoms of these elements, if they ever were present at the Earth's formation, have long since decayed.