Question 5 :
It was known by 1900 that the atom was not a............. , ................particle but contained at least one sub-atomic particle the electron identified by J.J. Thomson. 
Question 8 :
An atom of silicon has a mass number of $29$. How many neutrons does it have?  
Question 14 :
State whether the given statement is true or false:<br/>Nucleons are particles present in the nucleus of an atom.
Question 15 :
By changing the metal electrodes and gas inside the cathode ray tube,
Question 16 :
Almost the entire mass of an atom is concentrated in the :<br/>
Question 19 :
The mass of proton is_____  times the mass of an electron.
Question 20 :
The definitive experiments with cathode-ray tubes were done by ______ in 1879.
Question 21 :
___________ said that cathode rays consist of negatively charged particles and these were named as electrons.
Question 24 :
Goldsteins experiments which involved passing high voltage electricity through gases at very low pressure resulted in the discovery of:
Question 25 :
Goldstein's work with anode rays of $H^+$ was apparently the first observation of the :
Question 27 :
Electrons are the kind of particles which revolve around the nucleus.
Question 29 :
Which of the following is true for mass and charge of proton?
Question 31 :
Oxygen consists of isotopes ${{\text{O}}^{16}}\,$,${{\text{O}}^{17}}\,$ and ${{\text{O}}^{18}}\,$ carbon consists of isotopes of ${{\text{C}}^{{\text{12}}}}$ and ${{\text{C}}^{{\text{13}}}}$ Total number of ${\text{C}}{{\text{O}}_2}$ molecules possible are
Question 32 :
Which of the following is true for mass and charge of electron?
Question 33 :
Proton is formed by the loss of electron from which atom/ion?
Question 36 :
The cathode rays tube experiments carried out by J.J. Thomson demonstrated that :
Question 39 :
According to J.J Thomson's atomic model, negative charges are embedded in:
Question 40 :
In which of the following transformations, the $\beta $-particles are emitted?
Question 41 :
During the transformation of $_{ c }^{ a }{ X }$ to $_{ d }^{ b }{ Y }$, the number of $\beta $-particles emitted are
Question 46 :
If an atom contains one electron and one proton, what charge will it carry?
Question 48 :
Who said that cathode rays consist of negatively charged particles ?