Thomson's Discovery of Electrons

Q.

Which one of the following will have the maximum charge/mass ratio?

1. Electron

2. Proton

3. Neutron

4. Alpha particle.

Q. The constancy of $\frac{e}{m}$ ratio for electrons inspite of variation of gas present in the discharge tube or of the material of the cathode shows that

1. electrons are negatively charged.
2. electrons are universal constituents of matter.
3. electrons are the lightest of all particles.
4. mass of the electrons is of the mass of H-atom.

Q.

38. A stationary ${He}^{+}$ ion emitted a photon corresponding to the first line of H of Lyman series. The photon liberated photoelectron from a stationary H atom in the ground state. What is the velocity of electron.

Q.

The mass of an electron is about $\frac{1}{2000}$times that of a proton.

1. True
2. False

Q. In an atom, which has 2K, 8L, 18M and 2N electrons in the ground state .The total number of electrons having magnetic quantum number , m=0

Q. According to Thomson model, an atom possesses a spherical shape in which the positive charge is accumulated at the centre.

1. True

2. False

Q.

The number of possible spatial orientations of an electron in an atom is given by its

1. spin quantum number
2. magnetic quantum number
3. Azimuthal quantum number
4. orbital angular momentum

Q. Which of the following statements is incorrect about Thomson’s model of the atom?

1. The negative charge is uniformly distributed and the positive charge is embedded throughout like raisins
2. The positive charge is uniformly distributed in which the negatively charged electrons are embedded like raisins
3. Thomson’s model of the atom explains the electrical neutrality of an atom
4. The charge of the atom is non-uniformly distributed over the atom

Q. 21. Calculate the molarity of one kg of electrons in 500ml of solution

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

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

Q. 66. How does magnetic moment depend on number of unpaired electrons?

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. Which of the following statements is correct about Thomson’s model of the atom?

1. The mass of the atom is uniformly distributed over the atom
2. The mass of the atom is concentrated in very small portion of the atom
3. The size of an atom can be predicted by Thomson’s model of the atom
4. An atom is elliptical in shape

Q. If lone pair of electrons should always be kept on equitorial plane then why it is not one square pyramidal shape? Topic: Hybridization.

Q. find no of moles of electrons in 64 g CH4

Q. 10. What is the nature of cathode rays

Q. Which quantum number distinguishes the electron present in the same orbital of an atom?
A. Azimuthal quantum number
B. Magnetic quantum number
C. Principal quantum number
D. Spin quantum number

Q.

What is the mass of 4 moles of aluminium atoms (Atomic mass of aluminium = 27)

Q. 18.Number of electrons involved in the electrodeposition of 63.5 gm. of Cu from a solution of CuSO4 is (a) 6.022 × 10 23 (b) 3.011 × 10 23 (c) 12.044 × 10 23 (d) 6.022 × 10 22

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. Electrons emitted from various sources using different methods:

1. Have the same e/m values
2. have different e/m values
3. e/m value depends on the temperature
4. has e/m value equal to 1

Q. what is difference between light and electromagnetic waves ?

Q.

during orbital overlap , why should pairing electrons have opposite spins? why does the potential energy increase if they have the same spins?

Q. If the expansion is quasi-static, then the magnitude of q is ______.

1. 120 kJ
2. 60 kJ
3. 80 kJ
4. 40 kJ

Q. (i) calculate the number of electrons which will together weigh one gram

Q. Statement - 1: Thomson’s model of the atom suggests that an atom has an elliptical shape.
Statement - 2: Thomson’s model of the atom explains the electrical neutrality of the atom.

1. TT
2. TF
3. FT
4. FF

Q.

1. Calculate the ratio between the wavelength of an electron and a proton if the proton is moving with half the velocity of electron.

(Mass of proton = 1.67 X 10^-27 kg, Mass of electron = 9.11 X 10^-31 kg)

Q.

if an electron proton possess same de-Broglies wavelength velocity of electron V m/s then what will be the approx. velocity of proton.?

Q.

Mass of a neutron is more than mass of a proton.

1. True

2. False

Q.

Differencesbetween principal quantum no, azimuthal quantum no, magnetic quantum no and electron spin.(ANY6 points).