He discovered rays, invisible to the eye but NOT xray or cathodrays (have been discovered prior) but radioactive rays.
There are currently 38 radioactive elements that have been discovered. These elements have unstable nuclei that undergo radioactive decay, emitting radiation in the form of alpha particles, beta particles, or gamma rays.
The name for the emissions of rays and particles by a radioactive material are called radioactive decay. There are many different types of radioactive decay that emit different rays and particles.
discovered polonium discovered the existence of radium found how to isolate the radium metal discovered that thorium was a radioactive element discovered that uranium rays give conductivity to the air surrounding them
radioactive
You think probable to beta rays, gamma rays, alpha rays.
No. Gamma rays will not make materials radioactive.
Both beta rays and gamma rays are the products of radioactive decay and are the result of changes in atomic nuclei. X-rays can be generated by using high voltage to accelerate electrons and slam them into a metal target, so they might be said to be non-radioactive.
Roentgen was a scientist who investigated radiation. ----------------------------------- He discovered x-rays. Took the first x-ray of his wife's hand, when she saw it she was upset and remarked something about seeing her death.
Lead is commonly used to absorb radioactive rays due to its high density and ability to effectively block radiation. Other metals such as tungsten and uranium can also absorb radioactive rays to varying degrees.
Johann Wilhelm Ritter discovered ultraviolet rays
Many objects in the universe emit rays, such as stars emitting light rays, radioactive elements emitting gamma rays, and X-ray machines emitting X-rays. Rays can also be emitted from phenomena like solar flares, cosmic rays, and radioactive decay.