Chemistry Chapter 5 key concepts
Why did Rutherford’s atomic model need to be replaced?
Rutherford’s atomic model could not explain the chemical properties of elements.
What was the basic new proposal in the Bohr model of the atom?
Bohr proposed that an electron is found only in specific circular paths, or orbits, around the nucleus.
What does the quantum mechanical model determine about electrons in atoms?
The quantum mechanical model determines the allowed energies an electron can have and how likely it is to find the electron in various locations around the nucleus.
How do two sublevels of the same principal energy level differ from each other?
Each energy sublevel corresponds to an orbital of different shape describing where the electron is likely to be found.
What are the three rules for writing the electron configuration of elements?
Three rules – the aufbau principle, the Pauli exclusion principle; and Hund’s rule – tell you how to find the electron configurations of atoms.
Explain why the actual electron configurations for some elements differ from those assigned using the aufbau principle.
Some actual electron configurations differ from those assigned using the aufbau principle because half-filled sublevels are not as stable as filled sublevels, but they are more stable that other configurations.
How are wavelength and frequency of light related?
The wavelength and frequency of light are inversely proportional to each other. (example: as the wavelength of light increases, the frequency decreases)
Describe the cause of atomic emission spectrum of an element.
When atoms absorb energy, electrons move into higher energy levels, and these electrons lose energy by emitting light when they return to lower energy levels.
How is the change in electron energy related to the frequency of light emitted in atomic transitions?
The light emitted by an electron moving from a higher to a lower energy level has a frequency directly proportional to the energy changed of the electron.
How does quantum mechanics differ from classical mechanics?
Classical mechanics adequately describes the motions of bodies much larger than atoms, while quantum mechanics describes the motions of subatomic particles and atoms as waves.