1.explain how the concept of atomic number led to the synthesis of new elements in the laboratory;

Because from the atomic number of an element we can predict some of its properties; the properties of elements are a periodic function of their atomic numbers. That is the periodic law which is basically used to synthesize new and understand existing and undiscovered elements

Explanation:

answer; /// i believe that the correct answer is (c)

atomic = no of protons.

mass number-atomic number = neutron number