How will you explain the observations of Rutherford's α-ray scattering experiment?
(i) Most of the space in an atom between the nucleus and revolving electrons is empty. So most of α-particles will pass through an atom without any deflection. Electrons may cause only minor deflections to α-particles.
(ii) Alpha particles (He2+) have two units of positive charge while the nucleus of gold contains 79 protons. The nucleus will repel the α-particles. Since the size of the nucleus is very small, so only a few α-particles will pass by its side and deflected by a small angle.
(iii) A very few α-particles (1 in 20000) may hit or try to hit the small nucleus and these will be deflected backwards through angles greater than 90°.
Write the electronic configuration of Cr3+. (At. No. of Cr = 24)
What is the difference in the origin of cathode rays and anode rays?
Cathode rays consist of negatively charged material particles called electrons. These rays deflect towards the positive plate of an electric field. The charge to mass (e/m) for the particles in the nature of the gas taken in the discharge tube.
Anode rays consists of positively charges material particles. These rays deflect towards the negative plate of an electric field.
Describe briefly Thomson model of an atom.