Question

Before the nuclear age, uranium was thought to be the end of the periodic table, but in the last 70

years, scientists have left nature behind and created _______ new elements.

Answer 1

In the last 70 years, scientists have synthesized 22 new transuranium elements, which are elements with atomic numbers greater than 92 like neptunium, extending the periodic table beyond its natural limits.

Step-by-step explanation:

Before the nuclear age, uranium was thought to be the end of the periodic table, but in the last 70 years, scientists have created 22 transuranium elements. These are elements with atomic numbers greater than 92 and do not occur naturally on Earth; they can only be produced synthetically in the laboratory through nuclear reactions.

For example, neptunium (element 93) was created by bombarding uranium-238 with neutrons. The discovery and synthesis of these elements have expanded the periodic table and deepened our understanding of atomic structure and nuclear chemistry.