Question 3 :
Which of the following is true for mass and charge of proton?
Question 4 :
The definitive experiments with cathode-ray tubes were done by ______ in 1879.
Question 5 :
An atom of silicon has a mass number of $29$. How many neutrons does it have?  
Question 7 :
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 12 :
___________ said that cathode rays consist of negatively charged particles and these were named as electrons.
Question 13 :
Compared to the mass of lightest nucleus the mass of an electron is only:<br>
Question 20 :
Who said that cathode rays consist of negatively charged particles ?
Question 21 :
The mass of proton is_____  times the mass of an electron.
Question 23 :
In which of the following transformations, the $\beta $-particles are emitted?
Question 26 :
The cathode rays tube experiments carried out by J.J. Thomson demonstrated that :
Question 29 :
Electrons are the kind of particles which revolve around the nucleus.
Question 32 :
Almost the entire mass of an atom is concentrated in the :<br/>
Question 33 :
During the transformation of $_{ c }^{ a }{ X }$ to $_{ d }^{ b }{ Y }$, the number of $\beta $-particles emitted are
Question 36 :
State whether the given statement is true or false:<br/>Nucleons are particles present in the nucleus of an atom.
Question 37 :
Which of the following is true for mass and charge of electron?
Question 38 :
If an atom contains one electron and one proton, what charge will it carry?
Question 39 :
By changing the metal electrodes and gas inside the cathode ray tube,
Question 41 :
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 42 :
According to J.J Thomson's atomic model, negative charges are embedded in:
Question 45 :
Proton is formed by the loss of electron from which atom/ion?
Question 46 :
Goldstein's work with anode rays of $H^+$ was apparently the first observation of the :
Question 48 :
Goldsteins experiments which involved passing high voltage electricity through gases at very low pressure resulted in the discovery of:
Question 51 :
Through the body of every person, millions of tiny particles pass through silently every second. What are these particles?
Question 53 :
How much coulomb charge is present on $1 \,g$ ion of $N^{3-}$?
Question 54 :
Cathode rays are a stream of fast moving particles that travel in random directions.
Question 56 :
Which of the following factors increase the magnitude of deflection of cathode rays in discharge tube?
Question 58 :
The value of charge on the oil droplets experimentally observed were $-1.6 \times 10^{-19}$ and $-4 \times 10^{-19}$ coulomb. The value of the electronic charge, indicated by these results is:<br/>
Question 61 :
The ratio of specific charge of an $\alpha$-particle to that of a proton is:
Question 67 :
State True or False.<br/>Anode rays deflect towards anode in the presence of an electric field.
Question 68 :
The cathode rays tube experiments carried out by J.J. Thomson demonstrated that:<br/>
Question 69 :
The $\displaystyle \frac {e}{m}$ ratio of an electron for all types of substances is :
Question 70 :
In the path of the cathode rays, a tungsten metal is placed in the way. Then the rays produced are:
Question 72 :
The atomic weight of an element is $23$ and its atomic number is $11$. The number of proton, electrons and neutrons respectively, present in the atom of the element are
Question 73 :
The subatomic particle which remains unchanged during the chemical reaction is/are ________ . 
Question 74 :
An oil drop has $6.39 \times 10^{-19}\ C$ charge. What will be the number of electrons in this drop?
Question 77 :
The purpose of electron gun in a cathode ray tube is :
Question 79 : Match column A (name of the Scientists) with column B (their contributions towards the understanding of the atomic structure).<br/><table class="table table-bordered"><tbody><tr><td> Column A</td><td> Column B</td></tr><tr><td> A. Ernest Rutherford</td><td> 1. Indivisibility of atoms</td></tr><tr><td> B. J.J Thompson</td><td> 2. Stationary orbits</td></tr><tr><td> C. Dalton</td><td> 3. Concept of nucleus</td></tr><tr><td> D. Neils Bohr</td><td> 4. Discovery of electrons</td></tr><tr><td> E. James Chadwick</td><td> 5. Atomic number</td></tr><tr><td> F. E Goldstein</td><td> 6. Neutron</td></tr><tr><td> G. Moseley</td><td> 7. Canal rays</td></tr></tbody></table>
Question 80 :
The cathode ray experiment is conducted in a discharge tube containing four different gases A, B, C and D, the molecular weight of A = B > D > C, then e/m as observed will be:
Question 83 :
Which of the following is not a postulate given by Rutherford?
Question 85 :
Which experiment is responsible for finding out the charge on an electron?
Question 91 :
Assertion: Cathode rays get deflected towards the positive plate of electric field.
Reason: Cathode rays consist of negatively charged particles known as electrons.
Question 93 :
The ratio of the "e/m" (specific charge ) values of a electron and an $\alpha- $ particle is :
Question 94 :
In $\beta$-emission from a radioactive substance, an electron is ejected from:
Question 96 :
Which of the following is correct for cathode rays in discharge tube?
Question 98 :
The increase order for the value of $e/m$ (charge to mass ratio) for electron $(e)$, proton $(p)$; neutron $(n)$ and alpha particle $(\alpha)$ is:
Question 99 :
Which of the following contributes the least toward the atomic mass of an element?
Question 101 :
Among the following, the correct statement about cathode ray discharge tube is: 
Question 102 :
Assertion: e/m ratio in case of anode ray experiment is different for different gases.
Reason: The ion of gases formed after the ejection of electron are different if gas is different.
Question 104 :
The oil drop experiment by R.A. Mulliken was performed to find :
Question 105 : Match the column- I with Column - II and select the correct answer:<br/><table class="wysiwyg-table"><tbody><tr><td>Column - I</td><td>Column -II</td></tr><tr><td>(I) Curie</td><td>A. $10^6 \, dis \, sec^{-1}$</td></tr><tr><td>(II) Rutherford</td><td>B. $3.7 \times 10^{10} \, dis\, sec^{-1}$</td></tr><tr><td>(III) Becquerel</td><td>C. 1 dis $sec^{-1}$</td></tr></tbody></table>
Question 107 :
If the mass of electron is doubled, the speed of electron revolving around $Li^{2+}$ nucleus will ________
Question 108 :
A beam of some kind of particle of velocity $2\times {10}^{7}m/s$ is scattered by a gold $(z=79)$ foil. Find specific charge of this particle (charge/mass) if the distance of closest approach is $7.9\times {10}^{-14}m$.
Question 109 :
The mass and charge of one mole of electrons, respectively is:
Question 110 :
In an oil drop experiment, the following charges (in arbitary units) were found on a series of oil droplets:<br/>2.30 $\times$ 10$^{-15}$, 6.90 $\times$ 10$^{-15}$, 1.38 $\times$ 10$^{-14}$<br/>5.75 $\times$ 10$^{-15}$, 3.45 $\times$ 10$^{-15}$, 1.96 $\times$ 10$^{-14}$<br/>The magnitude of charge on the electron (in the same unit) is:
Question 111 :
Assertion: The characteristics of cathode rays do not depend upon the material of electrodes and the nature of the gas present in the cathode ray tube.
Reason: Cathode rays consist of negatively charged particles, called electrons.
