Question

1. what type of radiation is produced when high speed electrons strike a metal target? 2. how was this type of radiation from question one first detected? 3. what was becquerel studying in his lab and this led to the discovery of what?

Explanation:

1. When high - speed electrons strike a metal target, X - rays are produced. This is due to the sudden deceleration of electrons which causes the emission of electromagnetic radiation in the X - ray region.
2. X - rays were first detected when they caused a fluorescent screen to glow. Wilhelm Röntgen noticed that a screen coated with barium platinocyanide would fluoresce when placed near a cathode - ray tube, even though the tube was shielded by black cardboard.
3. Henri Becquerel was studying the fluorescence of uranium salts. He accidentally discovered radioactivity when he found that uranium salts exposed a photographic plate in the dark, without any external source of light.

Answer:

1. X - rays
2. By observing the fluorescence of a screen (barium platinocyanide screen near a cathode - ray tube).
3. He was studying uranium salts' fluorescence and discovered radioactivity.