⇦ | ⇨ |
The wavelength of kα, X-rays produced by an X-ray tube 0.76Å. The atomic number of the anode material of the tube is
Options
(a) 20
(b) 60
(c) 41
(d) 80
Correct Answer:
41
Explanation:
Given, wavelength, λ(kα) = 0.76 Å = 0.76 × 10⁻¹° m
Moseley’s empirical formula for Kα X-rays when adapted to Bohr model is given by,
hʋ(Kα) = (3/4) × 13.6 (Z-1)² eV
hc/λ(kα) = (3/4) × 13.6 × 1.6 × 10⁻¹⁹ (Z-1)² J
[Since, 1 eV = 1.6 × 10⁻¹⁹ J]
We know that, h = 6.626 × 10⁻³⁴ J-s and c = 3 × 10⁸ ms⁻¹
Substituting the values in the above equations, we get
(6.626 × 10⁻³⁴ × 3 × 10⁸)/(0.76 × 10⁻¹°) = 16.08 × 10⁻¹⁹ (Z-1)²
26.15 × 10⁻¹⁶ = 16.03 × 10⁻¹⁹ (Z-1)²
1.63 × 10³ = (Z-1)² ⇒ 16.3 × 10² = (Z-1)²
⇒ Z – 1 = 40.4 ⇒ Z = 40.4 + 1 ≈ 4.1
Related Questions: - If the binding energy of the electron in a hydrogen atom is 13.6 eV, the energy
- A long straight wire carrying current of 30A is placed in an external uniform
- The displacement of an object attached to a spring and executing simple harmonic
- The number of NAND gates required to form an AND gate is
- Suppose for some reasons, radius of earth were to shrink by 1% of present value,
Topics: Atoms and Nuclei
(136)
Subject: Physics
(2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- If the binding energy of the electron in a hydrogen atom is 13.6 eV, the energy
- A long straight wire carrying current of 30A is placed in an external uniform
- The displacement of an object attached to a spring and executing simple harmonic
- The number of NAND gates required to form an AND gate is
- Suppose for some reasons, radius of earth were to shrink by 1% of present value,
Topics: Atoms and Nuclei (136)
Subject: Physics (2479)
Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
18000+ students are using NEETLab to improve their score. What about you?
Solve Previous Year MCQs, Mock Tests, Topicwise Practice Tests, Identify Weak Topics, Formula Flash cards and much more is available in NEETLab Android App to improve your NEET score.
Share this page with your friends
Leave a Reply