The Bohr Model of Atomic Structure AP Physics 2 FRQ – Exam Style Questions etc.
The Bohr Model of Atomic Structure AP Physics 2 FRQ
Unit 15: Modern Physics
Weightage : 15–18%
Exam Style Practice Questions ,The Bohr Model of Atomic Structure AP Physics 2 FRQ
Question
An atomic particle of mass m moving at speed v is found to have wavelength λ. What is the wavelength of a second particle with three times the speed and twice the mass?
A) 3λ/2 B) 2λ/3 C) 6λ D) λ/6
▶️Answer/Explanation
Ans:D
Solution: The de Broglie wavelength is given by p = h / λ. Since p = mv, λ = h / mv. Therefore, λnew =h/[(3m)(2v)] = λ/6.
Question
According to the Bohr theory of the hydrogen atom, electrons starting in the 4th energy level and eventually ending up in the ground state, could produce a total of how many lines in the hydrogen spectra?
A) 3 B) 4 C) 5 D) 6
▶️Answer/Explanation
Ans:
D
Solution: 4–3,3–2,2–1 … or 4–2, 2–1 … or 4–3, 3–1 … or 4–1 … this is a total of 6 different transitions.