The number in parentheses is not an atomic weight. It is the mass number of one radioactive isotope of the element.
Atomic weight from the Chemical Society of Japan, “Table of Standard Atomic Weights with Four Significant Figures (2026)”.
Up to element 101, mendelevium, almost all new elements were found in the United States. Most of them were discovered by the research team led by Seaborg.
In 1994, the United States proposed “seaborgium” for element 106, but it was first turned down because “there was no example of an element named after a living person.” After strong objections from the United States, it became the official name in 1997.
Seaborgium was found in the United States in 1974, made by smashing oxygen (number 8) into californium (number 98).
Seaborgium is in the seventh row of Group 6, at the bottom of the column with chromium, molybdenum and tungsten.
There is no single right answer. Talking it over with someone at home is a good way to learn.