Technetium is indeed the first element to be produced artificially. Its atomic number is 43, which means it has 43 protons in its nucleus.
However, the atomic weight of technetium varies because it exists in multiple isotopic forms. Isotopes are atoms of the same element that have different numbers of neutrons in their nuclei.
The most stable and common isotope of technetium is technetium-98 (Tc-98), which has an atomic mass of approximately 97.907 u (atomic mass units).
It's important to note that technetium-98 is a radioactive isotope with a relatively short half-life of about 4.2 million years. Other isotopes of technetium exist, but they are generally unstable and radioactive as well.
Therefore, the atomic number of technetium is 43, and the atomic weight of its most stable isotope, technetium-98, is approximately 97.907 u.