Activity 2.1 - X the unknown

• To be able to describe how X-rays were discovered
• To be able to explain what X-rays are and how they are produced

Let student watch the Science Channel's movie (2.5 min): Discovery of X-rays
(play via http://videos.howstuffworks.com/science-channel/29105-100-greatest-disco...). This short movie gives background information about the discovery of X-rays. Let students answer questions given in activity 1.

Activity 2 is an Exploration activity. Based on the given picture discuss with the students what X-rays are. Listen carefully to students, act as facilitator, ask questions if needed.

In activity 3, an Explanation activity, students learn how X-rays are produced. To be able to understand the theory students need to have some pre-knowledge about Bohr’s model of the atom, photons, energy levels of electrons, etc.

Activity 4, an Extension activity, goes deeper into the theory. By watching the YouTube movie ‘How does an X-ray Tube Work’ (http://www.youtube.com/watch?v=Bc0eOjWkxpU) students learn more about atom interactions which cause the X-ray radiation.
Encourage the students to explain their findings in own words.

• In which experiment X-rays were discovered?
• What are X-rays?
• What is the energy of X-rays?
• What is the wavelength of X-rays?
• How X-rays are produced?