Match the following:

$A$. Chadwick	$1$. Cathode rays
$B$. Rutherford	$2$. $X$-ray spectra
$C$. Moseley	$3$. Discovery of neutrons
$D$. $J$. $J$. Thomson	$4$. Nuclear atom model

The masses of an electron,a proton and a neutron respectively will be in the ratio

The charge on a positron is equal to the charge on which one of the following?

Which of the following statements is correct about the cathode rays?
$1$. These rays start from anode and move towards cathode.
$2$. They are visible with human eye.
$3$. In presence of electric and magnetic fields,they behave like positively charged particles.
$4$. Their characteristic does not depend on the nature of material at electrode.

Provide general information about the fundamental particles of an atom.

$A$ positron has a mass equal to that of a/an ...... .