Problem 111
Excessive exposure to sunlight increases the risk of skin cancer because some of the photons have enough energy to break chemical bonds in biological molecules. These bonds require approximately \(250-800 \mathrm{~kJ} / \mathrm{mol}\) of energy to break. The energy of a single photon is given by \(E=h c / \lambda\), where \(E\) is the energy of the photon in \(\mathrm{J}, h\) is Planck's constant \(\left(6.626 \times 10^{-34} \mathrm{~J} \cdot \mathrm{s}\right)\), and \(c\) is the speed of light \(\left(3.00 \times 10^{8} \mathrm{~m} / \mathrm{s}\right)\). Determine which kinds of light contain enough energy to break chemical bonds in biological molecules by calculating the total energy in \(1 \mathrm{~mol}\) of photons for light of each wavelength. (a) infrared light \((1500 \mathrm{~nm})\) (b) visible light ( \(500 \mathrm{~nm}\) ) (c) ultraviolet light ( \(150 \mathrm{~nm}\) )
Problem 113
Sketch the following orbitals (including the \(x, y\), and \(z\) axes): \(1 s, 2 p_{x}, 3 d_{x y}, 3 d_{z} 2\).
Problem 114
Draw the best periodic table you can from memory (do not look at a table to do this). You do not need to label the elements, but you should put the correct number of elements in each block. After your group agrees that the group has done its best, spend exactly three minutes comparing your table with Figure 9.26. Make a second periodic table from memory. Is it better than your first one?
