An elementary particle is:

Which of the following particles cannot be accelerated by an electric or magnetic field?

Which of the following statements regarding cathode rays is incorrect?

Fill in the blanks given below:
$(i)$ The picture on the television screen is visible due to the presence of .......... on the screen.
$(ii)$ In the presence of electric and magnetic fields,cathode rays are known as .......... .
$(iii)$ The measurement of the $e/m_e$ ratio for electrons was performed by the scientist .......... .
$(iv)$ In a cathode ray tube,the greater the magnitude of the charge on the particles,the .......... the deflection of the particles.

What is the ratio of the mass of a proton to the mass of an electron?

From which word is the term $Atom$ derived and what is its meaning?