The question consists of a certain number of sentences. Some sentences are grammatically incorrect or inappropriate. Select the option that indicates the grammatically incorrect and inappropriate sentence(s).
- Phosphorescence and fluorescence seem especially to result from the alpha and beta rays, particularly from the alpha rays, to which belongs the most important part of the total energy of the radiation.
- Sir W. Crookes has invented a curious little apparatus, the spinthariscope, who enables us to examine the phosphorescence of the blend excited by these rays.
- By means of magnifying glass, a screen covered with sulphide of zinc is kept under observation, and in front of it is disposed, at a distance of about half a millimetre, a fragment of some salt of radium.
- We then perceive multitudes of brilliant point on the screen, which appear and at once disappear, producing a scintillating effect.
- It seems probable that every particle falling on the screen produces by its impact a disturbance in the neighbouring region, and it is this disturbance which the eye perceives as a luminous point.