Table of contents

1. Intro to General Chemistry3h 48m
2. Atoms & Elements4h 16m
3. Chemical Reactions4h 10m
4. BONUS: Lab Techniques and Procedures1h 38m
5. BONUS: Mathematical Operations and Functions48m
6. Chemical Quantities & Aqueous Reactions3h 53m
7. Gases3h 49m
8. Thermochemistry2h 37m
9. Quantum Mechanics2h 58m
10. Periodic Properties of the Elements3h 9m
11. Bonding & Molecular Structure3h 29m
12. Molecular Shapes & Valence Bond Theory1h 57m
13. Liquids, Solids & Intermolecular Forces2h 23m
14. Solutions3h 1m
15. Chemical Kinetics2h 53m
16. Chemical Equilibrium2h 29m
17. Acid and Base Equilibrium5h 1m
18. Aqueous Equilibrium4h 47m
19. Chemical Thermodynamics1h 50m
20. Electrochemistry2h 42m
21. Nuclear Chemistry2h 36m
22. Organic Chemistry5h 7m
23. Chemistry of the Nonmetals2h 39m
24. Transition Metals and Coordination Compounds3h 16m

9. Quantum Mechanics

Bohr Equation

General Chemistry

9. Quantum Mechanics

Bohr Equation

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Multiple Choice

Using the Bohr equation, calculate the wavelength of light emitted when an electron in a hydrogen atom transitions from n=2 to n=1.

121 nm

486 nm

656 nm

434 nm

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Verified step by step guidance

Understand the Bohr model: The Bohr model describes the hydrogen atom with quantized energy levels. When an electron transitions between these levels, it emits or absorbs a photon with energy equal to the difference between the initial and final energy levels.

Identify the formula: The energy difference between two levels in a hydrogen atom can be calculated using the formula:

- \frac{R_{H} (n^{2})}{n^{2}}

, where

R_{H}

is the Rydberg constant (approximately 2.18 x 10^-18 J), and n is the principal quantum number.

Calculate the energy difference: Use the formula to find the energy difference between the two levels, n=2 and n=1. Substitute n=2 and n=1 into the formula to find the energy difference:

- \frac{R_{H} (n^{2})}{n^{2}}

Relate energy to wavelength: Use the equation

E = \frac{hc}{λ}

, where E is the energy difference, h is Planck's constant (6.626 x 10^-34 J·s), c is the speed of light (3.00 x 10^8 m/s), and λ is the wavelength. Rearrange the equation to solve for λ:

λ = \frac{hc}{E}

Substitute and solve: Substitute the values for h, c, and the calculated energy difference into the equation to find the wavelength of the emitted light. This will give you the wavelength in meters, which can be converted to nanometers (1 m = 10^9 nm) for the final answer.