chapter 5 Flashcards
region of high probability of finding an electron
atomic orbital
each orbital has at most two electrons
Pauli exclusion principle
discrete bundle of electromagnetic energy
photon
energy needed to move an electron from one energy level to another
quantum
number of wave cycles passing a point per unit of time
frequency
distance between wave crests
wavelength
separation of light into different wavelengths
spectrum
In the Bohr model of the atom, an electron in an orbit has a fixed
energy
What is the maximum number of f orbitals in any single energy level in an atom?
7
sub-level
like theater seats arranged in sections: letters s, p, d, and f
What is the maximum number of d orbitals in a principal energy level?
5
What is the maximum number of orbitals in the p sublevel?
3
What is the maximum number of electrons in the second principal energy level?
8
When an electron moves from a lower to a higher energy level, the electron
absorbs a quantum of energy
The shape (not the size) of an electron cloud is determined by the electron’s
energy sublevel
If the spin of one electron in an orbital is clockwise, what is the spin of the other electron in that orbital?
counterclockwise
What is the next atomic orbital in the series 1s, 2s, 2p, 3s, 3p?
4s
According to the aufbau principle,
electrons enter orbitals of lowest energy first
What is the number of electrons in the outermost energy level of an oxygen atom?
6
If three electrons are available to fill three empty 2p atomic orbitals, how will the electrons be distributed in the three orbitals?
one electron in each orbital
How many unpaired electrons are in a sulfur atom (atomic number 16)?
2
How many half-filled orbitals are in a bromine atom?
1
What is the basis for exceptions to the aufbau diagram?
Filled and half-filled energy sublevels are more stable than partially-filled energy sublevels.
Which electron configuration of the 4f energy sublevel is the most stable?
4f14
How does the speed of visible light compare with the speed of gamma rays, when both speeds are measured in a vacuum?
The speeds are the same
Which color of visible light has the shortest wavelength?
violet
How are the frequency and wavelength of light related?
They are inversely proportional to each other.
Emission of light from an atom occurs when an electron
drops from a higher to a lower energy level
As changes in energy levels of electrons increase, the frequencies of atomic line spectra they emit
increase
Which of the following quantum leaps would be associated with the greatest energy of emitted light?
n = 5 to n = 1
Which variable is directly proportional to frequency?
energy
relation between wavelength, frequency, and energy
λ↑V↓E↓
λ↓V↑E↑
The quantum mechanical model of the atom
involves the probability of finding an electron in a certain position
Who predicted that all matter can behave as waves as well as particles?
Louis de Broglie
According to the Heisenberg uncertainty principle, if the position of a moving particle is known, what other quantity CANNOT be known?
velocity
How can the position of a particle be determined?
by analyzing its interactions with another particle
The wavelike properties of electrons are useful in
magnifying objects
In an s orbital, the probability of finding an electron a particular distance from the nucleus does NOT depend on
direction with respect to the nucleus
What is the energy of a microwave photon that has a frequency of 1.12 10 Hz? (h = 6.63 10 Js)
.
Explain why the 4s sublevel fills before the 3d sublevel begins to fill as electrons are added.
Electrons occupy orbitals in a definite sequence, filling orbitals with lower energies first. Generally, orbitals in a lower energy level have lower energies than those in a higher energy level. But, in the third level the energy ranges of the principal energy levels begin to overlap. As a result, the 4s sublevel is lower in energy than the 3d sublevel, so it fills first.
Describe the different principles that govern the building of an electron configuration.
The aufbau principle states that electrons enter the orbitals of lowest energy first. The Pauli exclusion
principle states that each orbital can hold only two electrons. Hund’s rule states that electrons first enter separate orbitals of the same energy, with each electron having the same spin, before pairing with electrons that have opposite spins.
What is the explanation for the discrete lines in atomic emission spectra?
Atoms absorb energy, causing electrons to be raised from one orbital to an orbital of higher energy. When these excited electrons fall back to lower energy levels, they emit light. The lines result from the fact that the electrons can move only between discrete energy levels. Emissions of specific frequencies of light correspond to these energy changes.
Why are you unable to observe the wavelike motion of a soccer ball as it is kicked toward a goal?
The mass of an object must be very small in order to observe its wavelength. Classical mechanics describes the motions of objects much larger than atoms. The motion of objects with sizes in the atomic range and smaller are best described (and are detectable) as waves.
What is the quantum mechanical model?
It is a model that describes subatomic particles and atoms as waves. Schrodinger applied a mathematical model of the wave/particle nature of matter to hydrogen. Solutions to the Schrodinger equation determine the energies an electron can have and how likely it is to find the electron in various locations.
Explain what is meant by the Heisenberg uncertainty principle.
The measurement of the speed or position of a moving particle necessarily involves an interaction with the particle. Therefore, the position or the speed of the particle is changed as a result of the measurement. As a consequence, accurate measurements of both these variables cannot be made at the same time.
Principal Quantum Number
(n) the energy level of the electron: 1, 2, 3, etc.
Aufbau principle
electrons enter the lowest energy first
Pauli Exclusion Principle
- at most 2 electrons per orbital
- different spins
energy level
analogous to the rungs of a ladder
electrons cannot exist between levels
first energy level
Has only s orbital
only 2 electrons
second energy level
Has s and p orbitals available
2 in s, 6 in p
third energy level
Has s, p, and d orbitals
2 in s, 6 in p, and 10 in d
fourth energy level
Has s, p, d, and f orbitals
2 in s, 6 in p, 10 in d, and 14 in f
