Chemistry Quiz - 3.3 Properties of Waves: wavelength and frquency
What is the energy of an electron in a helium ion (He+) in an energy level of n=4? -Use 2.18×10-18 J for the Rydberg constant in joules (sometimes labeled Ry, R∞, or k).
-5.45 x 10^-19 J The atomic number, Z, of helium is 2; k=2.18×10-18 J; and the electron is characterized by an n value of 4 E = (-2.18 x 10^-18 J)(2)^2/4^2
What is the energy of the electron in a helium ion with a charge of +1 in an orbit with a value of n=4? -Use k = 2.18 × 10^−18J. -Report your answer with three significant figures.
-5.45 x 10^-19J Energy of the electron in a single-electron atom is: E = −kZ^2/n^2 k is the Rydberg constant (2.18×10−18 J), Z is the atomic number of the atom, and n is the energy level occupied by the electron E = -(2.18 x 10^-18)(2)^2/(4)^2
Calculate the change in energy for an electron of a hydrogen atom that is excited from a n=2 orbital to a n=6 orbital -Use 2.18×10−18J for the Rydberg constant
4.842 x 10^−19J First, write the Rydberg equation: ΔE= Ef − Ei ΔE = −2.18J × 10^−18 (1/6^2 - 1/2^2)
What is the maximum wavelength of photon that will eject a ground state electron from a hydrogen atom?
9.13 x 10^-8 m ΔE=hc/λ = −2.18×10−18J×[1/infinite -1/1]= [1/n2/2 -1/n2/1] (6.626×10^−34)(3×10^8)/λ = −2.18×10^−18 J×[1/∞-1/1] (1.9878 x 10^-25)/ λ = −2.18×10^−18J × (0-1) λ = 9.13 x 10^−8 m
If an electron transitions from n=4 to n=1, what will be the wavelength of the resulting photon emitted? -Use RH=2.18×10−18J for the hydrogen atom Rydberg constant. -Use h=6.626×10−34 Js for Planck's constant. -Use c=2.998×108ms for the speed of light.
9.724 x 10^-8 m First, determine the energy change for the transition from ni=4 to nf=1 using the Rydberg equation -> -2.0428 x 10^-18 J ΔE = hc/λ 2.0428 x 10^-18 J = (6.626 x 10^-34 Js)(2.998 x 10^8 m/s)/λ λ = (6.626 x 10^-34 Js)(2.998 x 10^8 m/s)/2.0428 x 10^-18 J
Which of the following is a feature of Bohr's one-electron system? -An electron's energy increases as its distance from the nucleus increases. -The energies of electrons in an atom are quantized. -Line spectra exhibit discrete energies as a result of quantized electronic energies. - All of the above
All of the above
Bohr's model of the hydrogen atom, which restricts electrons to circular orbits around the nucleus parameterized by a single number, n, can best be applied to which other species?
He+ Bohr's model applies to any atom with one electron, such as He+,Li2+,Be3+, etc. Multielectron atoms like He are affected by repulsion between electrons and yield a more complicated pattern of energy levels.
Bohr's model can be applied to which of the following? -Li^2+ -He+ -Be^3+ -all of the above
all of the above
As n increases, the distance between energy levels
decreases With each successive orbit, the distance to the next orbit becomes smaller.
What was a severe limitation of Bohr's model for the atom?
it only worked for one-electron systems
