Answer :
Final answer:
There are 118 known elements in science, out of which 92 occur naturally on Earth. The remaining elements are synthetic and mostly unstable, and some have only been recently added to the periodic table. The correct option is a.
Explanation:
Out of the 118 different elements known to science, only 92 elements are naturally occurring on Earth. The rest have been synthetically created in laboratories and tend to be highly unstable, often existing for mere seconds. This includes elements with atomic numbers ranging from about 93 to 118, which are not ordinarily found in nature. Moreover, many of these higher atomic number elements were only recently confirmed and added to the periodic table.
It's important to note that while there are about 90 elements with at least one stable isotope that occur naturally on Earth, technology has enabled us to discover and create nearly 30 additional elements. These synthetic elements are primarily used for research due to their short-lived existence.
