Question

Explain how you know that no new element with an atomic number less than 100 will be discovered

Answer 1

The elements are identified by its aomic number and they are placed in the periodic table in ascending order of atomic number.

There is one unique element for a given atomic number.

For example, atomic number 1 identifies Hydrogen and there cannot be another different element with the same atomic number.

All the elements with atomic numbers from 1 to 118 have been discovered. So, you know that there is not room for new products with atomic number equal or less than 118.