[close] Wilhelm Conrad Röntgen (/ˈrɛntɡən, -dʒən, ˈrʌnt-/;[3] German pronunciation: [ˈvɪlhɛlm ˈʁœntɡən] (listen); 27 March 1845 – 10 February 1923) was a German mechanical engineer and physicist,[4] who, on 8 November 1895, produced and detected electromagnetic radiation in a wavelength range known as X-rays or Röntgen rays, an achievement that earned him the inaugural Nobel Prize in Physics in 1901.[5][6] In honour of Röntgen's accomplishments, in 2004 the International Union of Pure and Applied Chemistry (IUPAC) named element 111, roentgenium, a radioactive element with multiple unstable isotopes, after him. The unit of measurement roentgen was also named after him.

He was born to Friedrich Conrad Röntgen, a German merchant and cloth manufacturer, and Charlotte Constanze Frowein.[7] At age three his family moved to the Netherlands where his mother's family lived.[7] Röntgen attended high school at Utrecht Technical School in Utrecht, Netherlands.[7] He followed courses at the Technical School for almost two years.[8] In 1865, he was unfairly expelled from high school when one of his teachers intercepted a caricature of one of the teachers, which was drawn by someone else.

Without a high school diploma, Röntgen could only attend university in the Netherlands as a visitor. In 1865, he tried to attend Utrecht University without having the necessary credentials required for a regular student. Upon hearing that he could enter the Federal Polytechnic Institute in Zurich (today known as the ETH Zurich), he passed the entrance examination and began studies there as a student of mechanical engineering.[7] In 1869, he graduated with a PhD from the University of Zurich; once there, he became a favourite student of Professor August Kundt, whom he followed to the newly founded German Kaiser-Wilhelms-Universität in Strasbourg