The mass and charge of one mole of electrons are, respectively:
1. 5.48 × kg, 9.65 C
2. 5.48 × C, 1.098 × 1027
3. 5.48 × kg, 9.65 × C
4. 9.65 × C, 1.098 × 1027
What is the total number of electrons present in one mole of methane (CH₄)?
The total number and mass of neutrons in 7 mg of 14C would be :
(Assume that mass of a neutron = 1.675 × 10–27 kg)
\(1 .\) \(2 . 41\) \(\times\) \(\left(10\right)^{21}\) \(,\) \(4 . 03\) \(\times\) \(\left(10\right)^{– 6}\) \(kg\)
\(2 .\) \(6 . 23\) \(\times\) \(\left(10\right)^{23}\) \(,\) \(1 . 67\) \(\times\) \(\left(10\right)^{- 21} kg\)
\(3 .\) \(1 . 22\) \(\times\) \(\left(10\right)^{22}\) \(,\) \(4 . 03\) \(\times\) \(\left(10\right)^{6}\) \(kg\)
\(4 . 2 . 41\) \(\times\) \(\left(10\right)^{21}\) \(,\) \(4 . 03\) \(\times\) \(\left(10\right)^{- 6}\) \(g\)
The maximum number of neutrons are present in the nuclei of:
1. \(_8^{16}\mathrm{O}\)
2. \(_{12}^{24}\mathrm{Mg}\)
3.\(_{26}^{56}\mathrm{Fe}\)
4. \(_{38}^{88}\mathrm{Sr}\)
The complete symbol for the atom with the given atomic number (Z) and atomic mass (A) would be, respectively :
| i. | Z = 17 , A = 35. |
| ii. | Z = 92 , A = 233. |
| iii. | Z = 4 , A = 9. |
1.
2.
3.
4.
Yellow light emitted from a sodium lamp has a wavelength (λ) of 580 nm. The frequency (ν) and wave number of this yellow light would be, respectively:
1. 517 × 1014 s–1 , 172 × 106 m–1
2. 6.17 × 1014 s–1 , 1.72 × 106 m–1
3. 4.17 × 1014 s–1 , 2.72 × 106 m–1
4. 5.17 × 1014 s–1 , 1.72 × 106 m–1
The energy of the photon with a frequency of 3 × 1015 Hz is:
1. 1.988 × J
2. 1.588 × J
3. 1.288 × J
4. 2.988 × J
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
The number of photons of light with a wavelength of 4000 pm that provide 1J of energy would be:
A photon of wavelength 4 × 10–7 m strikes a metal surface, the work function of the metal being 2.13 eV. The kinetic energy of emission would be:
| 1. | 0.97 eV | 2. | 97 eV |
| 3. | 4.97 × eV | 4. | 5.84 × 105 eV |