The underlined phrase in the sentence, "The famous physicist, who discovered the element, received much acclaim and many prestigious awards." is "received much acclaim and many prestigious awards". It is an object phrase. In other words, it cannot stand alone. It is dependent on the subject, "The famous physicist". The phrase "who discovered the element" is a secondary phrase. It does not need to be in the sentence for the sentence to make sense. The sentence is correct when this clause is taken out. For example: "The famous physicist received much acclaim and many prestigious awards".