Consider the question. Ruthenium is a chemical element with symbol Ru and atomic number 44. It is a rare transition metal belonging to the platinum group of the periodic table. Like the other metals of the platinum group, ruthenium is inert to most other chemicals. The Russian-born scientist of Baltic-German ancestry and a member of the Russian Academy of Science Karl Ernst Claus discovered the element in 1844 at Kazan State University in Russia and named it after the Latin name of his homeland, Rus. Ruthenium is usually found as a minor component of platinum ores; the annual production is about 20 tonnes. Most ruthenium produced is used in wear-resistant electrical contacts and thick-film resistors. A minor application for ruthenium is in platinum alloys and as a chemistry catalyst.

Answer this question based on the passage: where is ruthenium found on the periodic table?
What is the step-by-step reasoning process to arrive at the answer: the platinum group?
To answer the above question, the relevant sentence is: It is a rare transition metal belonging to the platinum group of the periodic table.