Which of the following statements are true about the models of the atom? Supporting your answers with explanation.
1. Thomson's model of the atom depicted electrons distributed uniformly throughout a positively charged sphere.
2. In the Bohr model, specific energy levels correspond to specific radii for the electron orbits.
3. The absorption and emission lines in a spectrum occur because the nucleus has a net positive charge.
4. Rutherford realized that an atom had a very massive center (nucleus) because he split the nucleus and obtained huge amounts of energy.
5. The highest energy levels in an atom are close to E = 0 eV.
TRUE - Thomson's model, also known as the plum pudding model, was proposed by J.J. Thomson. It described the atom was a corpse composed of electrons swimming in a soup of positive charge, thus making the atom normally neutral.
TRUE - Bohr model quantifies the energy of the electron to certain levels when the electron is stable. Therefore, fixed radii correspond to fixed energy levels the electron can have in orbit of the ...
This solution provides detailed explanations of the answers to the given true or false questions.
1.) In a Rutherford scattering experiment, an α-particle (charge = +2e) heads directly toward a gold nucleus (charge = +79 e). The -particle had a kinetic energy of 4.9 MeV when very far (r -> ∞ ) from the nucleus. Assuming the gold nucleus to be fixed in space, determine the distance of closest approach. (Hint: Use conservation of energy with PE = keq1q2/r.)
2.) What is the energy of the photon that, when absorbed by a hydrogen atom, could cause the following?
(a) an electronic transition from the n = 2 state to the n = 4 state
(b) an electronic transition from the n = 4 state to the n = 7 state
3.) Two hydrogen atoms collide head-on and end up with zero kinetic energy. Each then emits a 121.6 nm photon (n = 2 to n = 1 transition). At what speed were the atoms moving before the collision?
(a) Find the energy of the electron in the ground state of triply ionized beryllium, which has an atomic number Z = 4.
(b) Find the radius of its ground-state orbit.
5.) The K-shell ionization energy of copper is 8979 eV. The L-shell ionization energy is 951 eV. Determine the wavelength of the K_α emission line of copper. What must the minimum voltage be on an x-ray tube with a copper target in order to see the K_α line?