An atom of an element contains 29 electrons and 35 neutrons. The number of protons in the element would be:
1. | 29 | 2. | 35 |
3. | 6 | 4. | 64 |
If the diameter of a carbon atom is 0.15 nm, the number of carbon atoms that can be placed side by side in a straight line across the length of the scale of length 20 cm long will be:
1. | 1.33 × 107 | 2. | 5.46 × 108 |
3. | 1.33 × 109 | 4. | 2.36 × 108 |
The charge on the oil drop is –1.282 × 10–18C. The number of electrons present in it would be :
1. 15
2. 8
3. 2
4. 6
An element with a mass number of 81 contains 31.7% more neutrons as compared to protons. The atomic symbol of the element would be :
An ion with a mass number of 56 contains 3 units of positive charge and 30.4% more neutrons than electrons. The symbol of the ion is :
A nitrogen laser produces radiation at a wavelength of 337.1 nm. If the number of photons emitted is 5.6 × 1024,
the power of the laser is:
If the photon detector receives a total of 3.15 J from the radiation of 600 nm, the number of photons received by the detector would be:
A radiation source emitted 2.5 × 1015 photons in 2 nanoseconds. Energy of the source is :
Emission transitions in the Paschen series end at orbit n = 3 and start from orbit n and can be represented as v = 3.29 × 1015 (Hz) . The value of n if the transition is observed at 1285 nm is :
1. | 6 | 2. | 5 |
3. | 8 | 4. | 9 |
If the velocity of the electron is 1.6 × 106 . The de Broglie wavelength associated with this electron is: