7.E: Electronic Structure and Periodic Properties- Homework
Turn in your answers for the following questions - show your work
-
Write the electron configuration (ie: 1s
2
, 2s
1
), orbital energy diagram, and orbital box diagram for,
- H, and Na
- Be and Ca
- C and Ge
- Cl 1 - and K 1+
- Chlorophyll b absorbs light at a wavelength of 625 nm, what is the frequency (Hz) and energy (J) for a photon of light at this wavelength?
The Following Questions are for your practice - Do Not Turn In. They include answers so you can check your work
Electromagnetic Energy
-
An FM radio station found at 103.1 on the FM dial broadcasts at a frequency of 1.031 × 10
8
s
−1
(103.1 MHz). What is the wavelength of these radio waves in meters?
- answer
-
\(λ=\dfrac{c}{ν}\)
\(λ = \dfrac{2.998 \times10^{8}\: \dfrac{m}{s}}{1.031 \times10^{8}\: \dfrac{1}{s}} = 2.908\:m\)
-
A bright violet line occurs at 435.8 nm in the emission spectrum of mercury vapor. What amount of energy, in joules, must be released by an electron in a mercury atom to produce a photon of this light?
- answer
-
\(E= \dfrac{hc}{λ}\)
\(E= \dfrac{(2.998 \times 10^{8} \dfrac{m}{s})\: (6.6262 \times 10^{-34} Js)}{4.358 \times 10^{-7} m}\)
\(=4.56\times 10^{-19}J\)
The Bohr Model
-
Using the Bohr model, determine the energy in joules of the photon produced when an electron in a Li2+ ion moves from the orbit with n = 2 to the orbit with n = 1.
- answer
-
1.471 × 10−17 J
Development of Quantum Theory
-
Describe the properties of an electron associated with each of the following four quantum numbers:
n
,
l
,
m
l
, and
m
s
.
- answer
-
n determines the general range for the value of energy and the probable distances that the electron can be from the nucleus. l determines the shape of the orbital. m l determines the orientation of the orbitals of the same l value with respect to one another. m s determines the spin of an electron.
-
Identify the subshell in which electrons with the following quantum numbers are found:
- n = 2, l = 1
- n = 4, l = 2
- n = 6, l = 0
- answer
-
(a) 2 p ; (b) 4 d ; (c) 6 s
-
Consider the orbitals shown here in outline.
- What is the maximum number of electrons contained in an orbital of type (x)? Of type (y)?
- How many orbitals of type (x) are found in a shell with n = 2? How many of type (y)?
- Write a set of quantum numbers for an electron in an orbital of type (x) in a shell with n = 4. Of an orbital of type (y) in a shell with n = 2.
- What are the possible l and m l values for an orbital of type (x)? Of type (y)?
- answer
-
(a) x. 2, y. 2 ;(b) x. 1, y. 3 (c) x. 4 0 0 \(\dfrac{1}{2}\), y. 2 1 0 \(\dfrac{1}{2}\); (d) x. l = 0, m l = 0, y. l = 1, m l = –1, 0, or + 1
-
Write a set of quantum numbers for each of the electrons with an
n
of 4 in a Se atom.
- answer
-
n l m l s 4 0 0 \(+\dfrac{1}{2}\) 4 0 0 \(−\dfrac{1}{2}\) 4 1 −1 \(+\dfrac{1}{2}\) 4 1 0 \(+\dfrac{1}{2}\) 4 1 +1 \(+\dfrac{1}{2}\) 4 1 −1 \(−\dfrac{1}{2}\)
Periodic Variations in Element Properties
-
Using complete subshell notation (1
s
2
2
s
2
2
p
6
, and so forth), predict the electron configuration of each of the following atoms:
- C
- P
- answer
-
a.) 1s
2
2s
2
2p
2
b.) 1s 2 2s 2 2p 6 3s 2 3p 3
-
Use an orbital box diagram to describe the electron configuration of the valence shell of each of the following atoms:
- N
- answer
-
-
Which ion with a +1 charge has the electron configuration 1
s
2
2
s
2
2
p
6
3
s
2
3
p
6
3
d
10
4
s
2
4
p
6
? Which ion with a –2 charge has this configuration?
- answer
-
Rb + , Se 2 −
-
Based on their positions in the periodic table, predict which has the smallest atomic radius: Mg, Sr, Si, Cl, I.
- answer
-
Rb < Li < N < F
-
Based on their positions in the periodic table, list the following ions in order of increasing radius: K
+
, Ca
2
+
, Al
3
+
, Si
4
+
.
- answer
-
Si 4 + < Al 3 + < Ca 2 + < K +