Chemical Principles I Third Midterm Ch 6-9
Constants:
c = 3.00 x 108 m/s ; h = 6.63 x 10-34 J-s
1) What is an orbital? (5 pts)
An orbital is a mathematical function that describes the wave-like behavior of one
electron in an atom or molecule.
2) What is the difference in energy for a hydrogen atom with its electron in a 2s
orbital and in a 2p orbital? (3 pts)
None
Edn 9, Exercises 6-51,49
Edn 10, Exercises 6-59,57
3) Calculate the frequency of radiation that has a wavelength of 955 nm. (3 pts)
c / (3.00 x 108 m/s) / (955 x 10-9 m)
4) Calculate the energy of a photon of frequency 6.75 x 1012 s-1. (3 pts)
E = h 6.63 x 10-34 J-s) x (6.75 x 1012 s-1)
5) The physical property that demonstrates the wave-like behavior of light is called
diffraction . (3 pts)
6) Calculate the energy of a photon that is released when the electron in hydrogen
moves from n = 6 to n = 2. (RB = 2.18 x 10-18 J) (3 pts)
E = RB (1/nf2 - 1/ni2) = 2.18 x 10-18 J (1/22 – 1/62)
7) Fill in the numerical value of quantum numbers n and l corresponding to the
following orbital designations: (4 pts)
9Ex 6-43 10Ex 6-51 Orbital n
3p 3 1
2s 2 0
4f 4 3
5d 5 2
1
, 8) Fill in the maximum number of electrons that occupy each of the subshells in the
following table: (4 pts)
3d 4s 2p 5f
Max number e- 10 2 6 14
9Ex 6-55 10Ex 6-63
9) Write the electron configurations for the following atoms or ions, using the
appropriate noble-gas core abbreviations: (4 pts)
Electron configuration
Cs [Xe] 6s1
Cu [Ar] 4s1 3d10
Ni2+ [Ar] 3d8
Se2- [Ar] 4s2 3d10 4p6 or [Kr]
10) Fill in the quantum number(s) govern the following properties of orbitals: (4 pts)
Quantum number (or numbers)
shape l
energy n
spin ms
spatial orientation ml
11) Arrange the following atoms or ions in order of increasing size: (5 pts)
Lowest, middle, highest
Ca, Mg, Be Be, Mg, Ca
Ga, Br, Ge Br, Ge, Ga
Se2-, Te2-, Se Se, Se2-, Te2-
Co2+, Fe2+, Fe3+ Fe3+, Co2+, Fe2+
Ca, Ti4+, Sc3+ Ti4+, Sc3+, Ca
12) For each of the following pairs, circle the element with the higher metallic
character. (4 pts)
2
Constants:
c = 3.00 x 108 m/s ; h = 6.63 x 10-34 J-s
1) What is an orbital? (5 pts)
An orbital is a mathematical function that describes the wave-like behavior of one
electron in an atom or molecule.
2) What is the difference in energy for a hydrogen atom with its electron in a 2s
orbital and in a 2p orbital? (3 pts)
None
Edn 9, Exercises 6-51,49
Edn 10, Exercises 6-59,57
3) Calculate the frequency of radiation that has a wavelength of 955 nm. (3 pts)
c / (3.00 x 108 m/s) / (955 x 10-9 m)
4) Calculate the energy of a photon of frequency 6.75 x 1012 s-1. (3 pts)
E = h 6.63 x 10-34 J-s) x (6.75 x 1012 s-1)
5) The physical property that demonstrates the wave-like behavior of light is called
diffraction . (3 pts)
6) Calculate the energy of a photon that is released when the electron in hydrogen
moves from n = 6 to n = 2. (RB = 2.18 x 10-18 J) (3 pts)
E = RB (1/nf2 - 1/ni2) = 2.18 x 10-18 J (1/22 – 1/62)
7) Fill in the numerical value of quantum numbers n and l corresponding to the
following orbital designations: (4 pts)
9Ex 6-43 10Ex 6-51 Orbital n
3p 3 1
2s 2 0
4f 4 3
5d 5 2
1
, 8) Fill in the maximum number of electrons that occupy each of the subshells in the
following table: (4 pts)
3d 4s 2p 5f
Max number e- 10 2 6 14
9Ex 6-55 10Ex 6-63
9) Write the electron configurations for the following atoms or ions, using the
appropriate noble-gas core abbreviations: (4 pts)
Electron configuration
Cs [Xe] 6s1
Cu [Ar] 4s1 3d10
Ni2+ [Ar] 3d8
Se2- [Ar] 4s2 3d10 4p6 or [Kr]
10) Fill in the quantum number(s) govern the following properties of orbitals: (4 pts)
Quantum number (or numbers)
shape l
energy n
spin ms
spatial orientation ml
11) Arrange the following atoms or ions in order of increasing size: (5 pts)
Lowest, middle, highest
Ca, Mg, Be Be, Mg, Ca
Ga, Br, Ge Br, Ge, Ga
Se2-, Te2-, Se Se, Se2-, Te2-
Co2+, Fe2+, Fe3+ Fe3+, Co2+, Fe2+
Ca, Ti4+, Sc3+ Ti4+, Sc3+, Ca
12) For each of the following pairs, circle the element with the higher metallic
character. (4 pts)
2
