Problem 146
A carbon-oxygen double bond in a certain organic molecule absorbs radiation that has a frequency of \(6.0 \times 10^{13} \mathrm{s}^{-1}\) . a. What is the wavelength of this radiation? b. To what region of the spectrum does this radiation belong? c. What is the energy of this radiation per photon? per mole of photons? d. A carbon-oxygen bond in a different molecule absorbs radiation with frequency equal to \(5.4 \times 10^{13} \mathrm{s}^{-1} .\) Is this radiation more or less energetic?
Problem 147
Photogray lenses incorporate small amounts of silver chloride in the glass of the lens. When light hits the AgCl particles, the following reaction occurs: $$\mathrm{AgCl} \stackrel{h v}{\longrightarrow} \mathrm{Ag}+\mathrm{Cl}$$ The silver metal that is formed causes the lenses to darken. The enthalpy change for this reaction is \(3.10 \times 10^{2} \mathrm{kJ} / \mathrm{mol}\) . Assuming all this energy must be supplied by light, what is the maximum wavelength of light that can cause this reaction?
Problem 148
A certain microwave oven delivers 750 . watts \((\mathrm{J} / \mathrm{s})\) of power to a coffee cup containing 50.0 \(\mathrm{g}\) water at \(25.0^{\circ} \mathrm{C}\) . If the wave- length of microwaves in the oven is \(9.75 \mathrm{cm},\) how long does it take, and how many photons must be absorbed, to make the water boil? The specific heat capacity of water is 4.18 \(\mathrm{J} /^{\prime} \mathrm{C} \cdot \mathrm{g}\) and assume only the water absorbs the energy of the microwaves
Problem 149
Mars is roughly 60 million km from Earth. How long does it take for a radio signal originating from Earth to reach Mars?
Problem 151
One of the visible lines in the hydrogen emission spectrum corresponds to the \(n=6\) to \(n=2\) electronic transition. What color light is this transition? See Exercise 150 .
Problem 153
Are the following statements true for the hydrogen atom only, true for all atoms, or not true for any atoms? a. The principal quantum number completely determines the energy of a given electron. b. The angular momentum quantum number, \(\ell,\) determines the shapes of the atomic orbitals. c. The magnetic quantum number, \(m_{\ell},\) determines the direction that the atomic orbitals point in space.
Problem 154
Although no currently known elements contain electrons in g orbitals in the ground state, it is possible that these elements will be found or that electrons in excited states of known elements could be in \(g\) orbitals. For \(g\) orbitals, the value of \(\ell\) is \(4 .\) What is the lowest value of \(n\) for which \(g\) orbitals could exist? What are the possible values of \(m_{\ell} ?\) How many electrons could a set of \(g\) orbitals hold?
Problem 155
Which of the following orbital designations are incorrect: \(1 s,\) \(1 p, 7 d, 9 s, 3 f, 4 f, 2 d ?\)
Problem 156
The four most abundant elements by mass in the human body are oxygen, carbon, hydrogen, and nitrogen. These four elements make up about 96% of the human body. The next four most abundant elements are calcium, phosphorus, magnesium, and potassium. Write the expected ground-state electron configurations for these eight most abundant elements in the human body.
Problem 158
An ion having a \(4+\) charge and a mass of 49.9 u has 2 electrons with principal quantum number \(n=1,8\) electrons with \(n=2\) and 10 electrons with \(n=3 .\) Supply as many of the properties for the ion as possible from the information given. (Hint: In forming ions for this species, the 4\(s\) electrons are lost before the 3\(d\) electrons.) a. the atomic number b. total number of \(s\) electrons c. total number of \(p\) electrons d. total number of \(d\) electrons e. the number of neutrons in the nucleus f. the ground-state electron configuration of the neutral atom
