Example 7.1 Wavelength and Frequency

Transcription

1 Example 7.1 Wavelength and Frequency For Practice 7.1 A laser dazzles the audience in a rock concert by emitting green light with a wavelength of 515 nm. Calculate the frequency of the light.

2 Example 7.2 Photon Energy For Practice 7.2 A 100-watt lightbulb radiates energy at a rate of 100 J/s (The watt, a unit of power, or energy over time, is defined as 1 J/s.) If all of the light emitted has a wavelength of 525 nm, how many photons are emitted per second? (Assume three significant figures in this calculation.) For More Practice 7.2 The energy required to dislodge electrons from sodium metal via the photoelectric effect is 275 kj/mol. What wavelength in nm of light has sufficient energy per photon to dislodge an electron from the surface of sodium?

3 Example 7.3 Wavelength, Energy, and Frequency For Practice 7.3 Arrange these three colors of visible light green, red, and blue in order of increasing a. wavelength. b. frequency. c. energy per photon.

4 Example 7.4 De Broglie Wavelength For Practice 7.4 What is the velocity of an electron that has a de Broglie wavelength approximately the length of a chemical bond? Assume this length to be m.

5 Example 7.5 Quantum Numbers I For Practice 7.5 List the quantum numbers associated with all of the 5d orbitals. How many 5d orbitals exist?

6 Example 7.6 Quantum Numbers II For Practice 7.6 Each set of quantum numbers is supposed to specify an orbital. However, each set contains one quantum number that is not allowed. Replace the quantum number that is not allowed with one that is allowed. a. n = 3; l = 3; m l = +2 b. n = 2; l = 1; m l = 2 c. n = 1; l = 1; m l = 0

7 Example 7.7 Wavelength of Light for a Transition in the Hydrogen Atom For Practice 7.7 Determine the wavelength of the light absorbed when an electron in a hydrogen atom makes a transition from an orbital in which n = 2 to an orbital in which n = 7. For More Practice 7.7 An electron in the n = 6 level of the hydrogen atom relaxes to a lower energy level, emitting light of λ = 93.8 nm. Find the principal level to which the electron relaxed.

8 Electron Configurations For Practice 8.1 Write electron configurations for each element. a. Cl b. Si c. Sr d. O

9 Writing Orbital Diagrams For Practice 8.2 Write the orbital diagram for Ar and determine the number of unpaired electrons.

10 Valence Electrons and Core Electrons For Practice 8.3 Write an electron configuration for phosphorus. Identify the valence electrons and core electrons.

11 Example 8.4 Writing Electron Configurations from the Periodic Table For Practice 8.4 Use the periodic table to determine the electron configuration of bismuth (Bi). For More Practice 8.4 Use the periodic table to write the electron configuration for iodine (I).

12 Example 8.5 Atomic Size For Practice 8.5 On the basis of periodic trends, choose the larger atom in each pair (if possible): a. Sn or I b. Ge or Po c. Cr or W d. F or Se For More Practice 8.5 Arrange the elements in order of decreasing radius: S, Ca, F, Rb, Si.

13 Example 8.6 Electron Configurations and Magnetic Properties for Ions For Practice 8.6 Write the electron configuration and orbital diagram for each ion and predict whether each will be paramagnetic or diamagnetic. a. Co 2+ b. N 3 c. Ca 2+

14 Example 8.7 Ion Size For Practice 8.7 Choose the larger atom or ion from each pair. a. K or K + b. F or F c. Ca 2+ or Cl For More Practice 8.7 Arrange the following in order of decreasing radius: Ca 2+, Ar, Cl.

15 Example 8.8 Ionization Energy For Practice 8.8 On the basis of periodic trends, determine the element in each pair with the higher first ionization energy (if possible). a. Sn or I b. Ca or Sr c. C or P d. F or S For More Practice 8.8 Arrange the following elements in order of decreasing first ionization energy: S, Ca, F, Rb, Si.

16 Example 8.9 Metallic Character For Practice 8.9 On the basis of periodic trends, choose the more metallic element from each pair (if possible). a. Ge or Sn b. Ga or Sn c. P or Bi d. B or N For More Practice 8.9 Arrange the following elements in order of increasing metallic character: Si, Cl, Na, Rb.

17 Example 8.10 Alkali Metal and Halogen Reactions For Practice 8.10 Write a balanced chemical equation for each reaction. a. the reaction between aluminum metal and chlorine gas b. the reaction between lithium metal and liquid water c. the reaction between gaseous hydrogen and liquid bromine