Final answer:
The atomic number 43 of Technetium indicates that every atom of Technetium has 43 protons in its nucleus.
Step-by-step explanation:
The atomic number of an element, such as Technetium with an atomic number of 43, signifies the number of protons in the nucleus of each atom of that element. It is a unique identifier for each element on the periodic table. For Technetium (Tc), this means that every atom of Technetium has 43 protons in its nucleus. It's also worth noting that because Technetium has no stable isotopes, all its isotopes are radioactive, which is indicated on the periodic table with an atomic mass in square brackets.