Thomson's Discovery of Electrons

Q.

Write four characteristics properties of cathode rays.

Q.

The mass of a mole of proton and electron is
A. 1.007g and 0.55 mg
B.$9.11\times {10}^{-28}kgand9.1\times {10}^{-28}kg$
C. 2gm and 2gm
D.$6.023\times {10}^{23}gand6.023\times {10}^{23}g$

Q.

Find the Binding energy per nucleon for ${}_{50}{}^{120}\mathrm{Sn}$. Mass of proton ${\mathrm{m}}_{\mathrm{p}}=1.00783\mathrm{U}$, mass of neutron ${\mathrm{m}}_{\mathrm{n}}=1.00867\mathrm{U}$ and mass of tin nucleus ${\mathrm{m}}_{\mathrm{Sn}}=119.902199\mathrm{U}$. (take $1\mathrm{U}=931\mathrm{MeV}$)

1. $8.0\mathrm{MeV}$

2. $9.0\mathrm{MeV}$

3. $7.5\mathrm{MeV}$

4. $8.5\mathrm{MeV}$

Q. The ratio of the (e/m) ratio of an electron and an alpha particle is:

1. None of these
2. 1:1
3. 2:1
4. 1:2

Q.

The positively charged particles in an atom are called

1. neutrons

2. electrons

3. protons

4. none of these

Q.

Explain Zeeman and Starks effect.

Q.

Is oxygen negative or positive?

Q. Electrons and Neutrons were discovered respectively by:

1. J.J Thomson and E. Goldstein
2. E. Goldstein and E. Rutherford
3. J.J Thomson and J. chadwick
4. Both were discoverd by J.J thomson

Q.

Why light is an electromagnetic wave?

Q. The mass of cathode ray particle is:

1. Same for different gases
2. Different for different gases
3. Minimum for $H_2$ gas
4. Different for same gases

Q. Gases are generally maintained at very low pressures in a cathode ray tube:

1. To prevent collision between the atoms of the gas to form ions
2. To slow down the speed of a moving atom to show phosphorescence
3. To slow down the speed of moving ions to accept an electron
4. So that there is enough space for the electrons to accelerate and produce more electrons.

Q. Which of the following statements is correct regarding cathode rays?

1. They produce x-ray when they strike a metal
2. They ionize the gas which they pass through it
3. Cathode rays contain the smallest unit of negative charge
4. All of the above

Q. Gases are generally maintained at very low pressures in a cathode ray tube:

1. To prevent collision between the atoms of the gas to form ions
2. To slow down the speed of a moving atom to show phosphorescence
3. To slow down the speed of moving ions to accept an electron
4. So that there is enough space for the electrons to accelerate and produce more electrons.

Q.

What is the conventional direction of the flow of electric current? How does it differ from the direction of flow of electrons?

Q. Calculate the mass of a proton if the charge to mass ratio of an electron is $1.758820\times {10}^{11}{\text{C kg}}^{-1}$ and it is known that the mass of a proton is 1837 times greater than the mass of an electron.

1. $9.1\times {10}^{-31}$ kg
2. $6.4\times {10}^{31}$ kg
3. $6.02\times {10}^{23}$ kg
4. $1.67\times {10}^{-27}$ kg

Q. How we find out the charge carriers of a compound ? Pls explain me with examples for both complex and simple compound

Q.

How was the charge of an electron determined?

Q. Thomson's model of the atom is also called

1. Plum Pudding Model
2. Raisin Pudding Model
3. Watermelon Model
4. All of the above

Q.

How to determine the charge on electron?

Q. In the presence of an electric field, the cathode rays:

1. Travel in straight lines
2. Moves in a spiral motion
3. Deflect towards the positive plate
4. Exhibit no effect

Q.

WHY ARE CATHODE RAYS ARE CALLED CANAL RAYS?

Q.

Question 05

Which of the following statements about the electron is incorrect ?

(a) It is negatively charged particle

(b) The mass of electron is equal to the mass of neutron

(c) It is a basic constituent of all atoms

(d) It is a constituent of cathode rays

Q.

Find the total no. Of nucleons present in 12 g of C-12 atoms.

Q. Which of the following statements is the limitation of Thomson’s atomic model?

1. It failed to explain the electrical neutrality of an atom
2. It failed to explain how the positive charges hold the negative charges in an atom
3. The model could not explain the existence of electrons
4. None of these

Q.

Question 04

Which of the followig statement is not correct about the characteristics of cathode rays ?

(a) The start from the cathode and move towards the anode

(b) They travel in straight line in the absence of an external eletrical or magnetic field

(c) Characteristics of cathode rays do not depend upon the material of elctrodes in cathode ray tube

(d) Characteristics of cathode rays depend upon the nature of gas present in the cathode ray tube

Q.

Cathode rays consist of

1. Protons

2. Electrons

3. Neutrons

4. None of these

Q.

What is the absolute mass and charge of a proton?

Q. No of protons in 5 gm of water

Q. How does the lithium ion battery work and how does it gets charged?

Q.

Is a photon a particle or a wave?