Indietro
Problema 75
For each element, predict where the 'jump' occurs for successive ionization energies. (For example, does the jump occur between the first and second ionization energies, the second and third, or the third and fourth?) a. Be b. N c. O d. Li
Problema 76
Consider this set of ionization energies. IE1 = 578 kJ/mol IE2 = 1820 kJ/mol IE3 = 2750 kJ/mol IE4 = 11,600 kJ/mol To which third-period element do these ionization values belong?
Problema 77a
Choose the element with the more negative (more exothermic) electron affinity from each pair. a. Na or Rb
Problema 79
Choose the more metallic element from each pair. c. Cl or O
Problema 80
Choose the more metallic element from each pair. a. Sb or Pb b. K or Ge c. Ge or Sb d. As or Sn
Problema 81
Arrange these elements in order of increasing metallic character: Fr, Sb, In, S, Ba, Se.
Problema 82
Arrange these elements in order of decreasing metallic character: Sr, N, Si, P, Ga, Al.
- Bromine is a highly reactive liquid while krypton is an inert gas. Explain this difference based on their electron configurations.
Problema 83
- Potassium is a highly reactive metal while argon is an inert gas. Explain this difference based on their electron configurations.
Problema 84
Problema 85
Both vanadium and its 3+ ion are paramagnetic. Refer to their electron configurations to explain this statement.
- Refer to their electron configurations to explain why copper is paramagnetic, whereas its 1+ ion is not.
Problema 86
Problema 89
Life on Earth evolved based on the element carbon. Based on periodic properties, what two or three elements would you expect to be most like carbon?
- Explain why atomic radius decreases as you move to the right across a period for main-group elements but not for transition elements.
Problema 93
- Explain why vanadium (radius = 134 pm) and copper (radius = 128 pm) have nearly identical atomic radii, even though the atomic number of copper is about 25% higher than that of vanadium. Predict the relative densities of these two metals. Look up the densities in a reference book, periodic table, or on the Internet to check if your predictions are correct.
Problema 94
- The lightest noble gases, such as helium and neon, are completely inert—they do not form any chemical compounds whatsoever. In contrast, the heavier noble gases do form a limited number of compounds. Explain this difference in terms of trends in fundamental periodic properties.
Problema 95
- Why does the lightest halogen, which is also the most chemically reactive, exhibit a decrease in reactivity as you move down the column of halogens in the periodic table? Explain this trend in terms of periodic properties.
Problema 96
- What are the general outer electron configurations (nsx npy) for groups 6A and 7A in the periodic table? The electron affinity of each group 7A element is more negative than that of each corresponding group 6A element. Use the electron configurations to explain why this is so.
Problema 97
- Why is the electron affinity of each group 5A element more positive than that of each corresponding group 4A element? Use the outer electron configurations for these columns to suggest a reason for this observation.
Problema 98
Problema 99
The elements with atomic numbers 35 and 53 have similar chemical properties. Based on their electronic configurations, predict the atomic number of a heavier element that also should share these chemical properties.
Problema 101
You have cracked a secret code that uses elemental symbols to spell words. The code uses numbers to designate the elemental symbols. Each number is the sum of the atomic number and the highest principal quantum number of the highest occupied orbital of the element whose symbol is to be used. The message may be written forward or backward. Decode the following messages: a. 10, 12, 58, 11, 7, 44, 63, 66
Problema 103
Use Coulomb's law to calculate the ionization energy in kJ>mol of an atom composed of a proton and an electron separated by 100.00 pm. What wavelength of light has sufficient energy to ionize the atom?
Problema 104
The first ionization energy of sodium is 496 kJ/mol. Use Coulomb's law to estimate the average distance between the sodium nucleus and the 3s electron. How does this distance compare to the atomic radius of sodium? Explain the difference.
Problema 105
Consider the elements: B, C, N, O, F. d. Which element has three unpaired electrons?
Problema 106b
Consider the elements: Na, Mg, Al, Si, P. b. Which element has the smallest atomic radius?
Problema 106c
Consider the elements: Na, Mg, Al, Si, P. c. Which element is least metallic?
Problema 106d
Consider the elements: Na, Mg, Al, Si, P. d. Which element is diamagnetic?