red - Viene di seguito proposta una verifica scritta, realizzata dal prof. Helgesson Peter Ulf Johan nell'ambito delle lezioni per il CLIL di Fisica in lingua inglese, tenute presso il Liceo Scientifico “G. Ricci Curbastro”, Lugo (RA). L'argomento della verifica è il modello atomico di Bohr.
Answer to the following questions
1- Why did Bohr introduce the idea of “stationary state”?
2- How does one electron get into a higher-orbit?
3- What happens when the electron goes back to the lower orbit?
4-What is a photon? Who introduced it?
5- What is a quantum? Who introduced it?
6- How did Bohr explain visible light emission?
7- How did Bohr explain infrared and ultraviolet light emission?
8- What does “quantization of angular momentum” mean?
9-What is de Broglie’s hypothesis?
10- How do emission and absorption spectra differ?
Solve the following problems
1) A hydrogen atom is in its first excited state. Using the Bohr model of hydrogen, find:
a) the radius of the orbit of the electron;
b) the linear momentum of the electron in this atom;
b) the angular momentum of the electron in this atom;
c) the kinetic energy, potential energy, total energy of the electron, in eV.
2) Initially, an electron is in the first excited state of hydrogen.
If this electron acquires an additional 1.23 eV of energy, what is the value of the quantum number, n, in the final state of the electron?
3) Initially, an electron is in the third excited state of hydrogen.
The electron jumps to the ground state by emitting one photon.
a) Calculate the energy carried away by the emitted photon.
b) Calculate the frequency of the emitted light.
c) Calculate the wavelength of the emitted light.
FOCUS ON WORDS
Explain the meaning following words/sentences:
2- stationary states
3- allowed values
7- excited state
5- visible region
8- Explain the difference between the words “speed” and “velocity”