Which of the following statement is not correct about the characteristics of cathode rays?
1. | They start from the cathode and move towards the anode |
2. | They travel in straight line in the absence of an external electrical or magnetic field |
3. | Characteristics of cathode rays do not depend upon the material of electrodes in cathode ray tube |
4. | Characteristics of cathode rays depend upon the nature of gas present in the cathode ray tube |
1. | 2.4 ×10–19 g | 2. | 2.4 ×10–27 g |
3. | 2.4 ×10–24 g | 4. | None of these |
Correct statement about the properties of the atom explained by the Thomson
model of an atom is:
1. | Overall neutrality of atom |
2. | Spectra of a hydrogen atom |
3. | Position of electrons, protons, and neutrons in an atom |
4. | Stability of atom |
Which of the following conclusions could not be derived from Rutherford's -particle scattering experiment?
1. | Most of the space in the atom is empty. |
2. | The radius of the atom is about 10-10 m while that of a nucleus is 10–15 m. |
3. | Electrons move in circular path of fixed energy called orbits. |
4. | Electrons and the nucleus are held together by electrostatic forces of attraction. |
The number of protons, neutrons and electrons in \( _{71}^{175}Lu\) respectively, are:
1. 104, 71 and 71
2. 71, 71 and 104
3. 175, 104 and 71
4. 71, 104 and 71
The wave number of a light whose time period is 2.0 × 10–10 s would be:
1. 16.66 m–1
2. 1.66 m–1
3. 32.34 m–1
4. 12.34 m–1
2 × 108 atoms of carbon are arranged side by side. The radius of a carbon atom if the length of this arrangement is 2.4 cm would be :
1. 7.0 × 10–11 m
2. 5.0 × 10–11 m
3. 8.0 × 10–11 m
4. 6.0 × 10–11 m
The diameter of a zinc atom is 2.6 Å. If zinc atoms are arranged side by side lengthwise, number of atoms present in a length of 1.6 cm would be:
1. 5.153 × 107
2. 6.153 × 107
3. 4.153 × 109
4. 6.153 × 103
In Rutherford's experiment, generally, the thin foil of heavy atoms like gold, platinum, etc. have been used to be bombarded by the α-particles.
If the thin foil of light atoms like aluminum etc. is used in Rutherford’s experiment, the difference that would be observed from the above results is :
1. The same results will be observed.
2. More deflection would be observed.
3. There will not be enough deflection.
4. None of the above.
Symbols and can be written,
whereas symbols and are not acceptable because:
1. | The general convention for representing an element along with its atomic number (A) and atomic mass (Z) is |
2. | The general convention for representing an element along with its atomic mass (A) and atomic number (Z) is |
3. | The general convention for representing an element along with its wavelength (A) and frequency (Z) is |
4. | The general convention for representing an element along with its isotopes (A) and atomic number (Z) is |