The element used to increase number of free electrons in the semi-conductor belongs to: A. 4th Group B. 5th Group C. 2nd Group D. 3rd Group 0 0 votes Article Rating Subscribe Login Notify of new follow-up comments new replies to my comments Label {} [+] Name* Email* Label {} [+] Name* Email* 0 Comments Oldest Newest Most Voted Inline Feedbacks View all comments