Q. No.A certain particle carries 2.5 × 10–16 C of static electric charge. The number of electrons present in it would be:
1.
1460
2.
1350
3.
1560
4.
1660
In Rutherford's \(\alpha\)-particle scattering experiment, a thin foil of heavy metals like gold or platinum is typically used. If a lighter metal foil, such as aluminum, were used instead, how would the observed deflection patterns change?
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
Why are the symbols ⁷⁹₃₅Br, and ⁷⁹Br are considered acceptable, whereas ³⁵₇9Br and ³⁵Brand are not acceptable representations of bromine?
| 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 |
What is the correct arrangement of the following electromagnetic spectrum in the increasing order of frequency?
| 1. | Cosmic rays < Amber light < Radiation of FM radio < X-rays < Radiation from microwave ovens |
| 2. | Radiation from FM radio < Radiation from microwave oven < Amber light < X- rays < Cosmic rays |
| 3. | Radiation from microwave ovens < Amber light < Radiation of FM radio < X-rays < Cosmic rays |
| 4. | Cosmic rays < X-rays < Radiation from microwave ovens < Amber light < Radiation of FM radio |
The work function of the Cesium atom is \(1.9~\mathrm{eV}.\) What is the threshold frequency of radiation for this atom?
| 1. | \(4.59 \times10^{14}~s^{-1}\) | 2. | \(8.59 \times10^{14}~s^{-1}\) |
| 3. | \(5.59 \times10^{-14}~s^{-1}\) | 4. | \(65.9 \times10^{14}~s^{-1}\) |
1. 32.22 × 10–16 J
2. 12.22 × 10–16 J
3. 22.27 × 10–16 J
4. 31.22 × 10–16 J
If the position of the electron were measured with an accuracy of +0.002 nm, the uncertainty in the momentum of the electron would be:
1. 5.637 × 10–23 kg m s–1
2. 4.637 × 10–23 kg m s–1
3. 2.637 × 10–23 kg m s–1
4. 3.637 × 10–23 kg m s–1
1. 2p and 3p
2. 4p
3. 2p
The unpaired electrons in Al and Si are present in the 3p orbital. The electrons that will experience a more effective nuclear charge from the nucleus are :
1. Electrons in the 3p orbital of silicon
2. Electrons in the 5d orbital of aluminium
3. Electrons in the 3p orbital of aluminium
4. Electrons in the 5p orbital of silicon
Identify the element with the highest number of unpaired electrons in its ground state from the given options :
| 1. | P
|
2. | Fe
|
| 3. | Kr
|
4. | Cr |
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