tossup #1–families and periods Which element is a halogen in the third period? chlorine (Cℓ) chemistry unit 6 review bonus #1–atomic size trends chemistry unit 6 review Rank the size of a chlorine atom among F, Se, Br, and Ne atoms. Arrange them smallest to largest. Ne < F < Cℓ < Br < Se tossup #2–electron configuration chemistry unit 6 review What neutral element has electron configuration [Kr] tin 50Sn 2 5s 10 4d 2 5p bonus #2–categories chemistry unit 6 review Name a metalloid in the same family as tin. Silicon (Si) and/or germanium (Ge). Metalloids are at the boundary between metals and non-metals, along the zig-zagging dividing line. tossup #3–ions chemistry unit 6 review What is the common stable ion of rubidium (37Rb) and what is its complete electron configuration? Rb+: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 Rb has 1 valence electron, therefore it normally forms a +1 ion (by losing that one valence electron). It then has 36 electrons (like Kr). bonus #3–ion size trends chemistry unit 6 review Rank the sizes (from smallest to largest) of Rb+ and the isoelectronic ions Sr+2 and Br–. Briefly explain the reason for this ranking. Sr+2 < Rb+ < Br– 38 p+ vs. 37 p+ vs. 35 p+ All have 36 electrons and a [Kr] configuration. More protons attract the electron cloud more strongly and decrease the ion's size. tossup #4–valence electrons chemistry unit 6 review State the valence electron configurations of both phosphorus and antimony (15P and 51Sb). P: Sb: 3s2 3p3 5s2 5p3 bonus #4–columns chemistry unit 6 review Give three different names for the column in the periodic table that contains both phosphorus and antimony (P and Sb). column 5 group 5 nitrogen family pnictogens tossup #5–first ionization energy chemistry unit 6 review Which group 4 element has the greatest first ionization energy? carbon (C) bonus #5–first ionization energy chemistry unit 6 review Given that lithium and carbon have first ionization energies of 5.4 and 11.3, respectively, estimate the ionization energies for the rest of the period 2 elements. [These are in units of eV.] Li Be B 5.4 C N O F Ne 11.3 The ionization energies generally increase across the period, but decrease slightly at groups 3 & 6. Li Be B C N O F Ne 5.4 9.3 8.3 11.3 14.5 13.6 17.4 21.5 tossup #6–valence electrons Name the third-period element with six valence electrons. sulfur (S) chemistry unit 6 review bonus #6–successive ionization energies If an element's atoms have the ionization energies shown at right, what charge do its ions usually have in nature and what is the name of that element's family? chemistry unit 6 review 1st I.E. 2nd I.E. 3rd I.E. 4th I.E. 5th I.E. 6th I.E. 15.3 eV 28.7 eV 91.2 eV 157 eV 893 eV 1330 eV This element would generally form +4 ions and is in the carbon family. Four easier ionizations indicate an atom with four valence electrons. Carbon family elements have four valance electrons. Valence electrons are easier to remove than core electrons. tossup #7–atom and ion sizes chemistry unit 6 review Which is the smallest among the following atoms and ions? K, Ca2+ + K, Ca, 2+ Ca bonus #7–atom and ion sizes chemistry unit 6 review Choose the smallest in each of the following pairs and explain why it is smaller. K or Ca + K or 2+ Ca Ca is smaller than K. They have a similar valence electrons (1 or 2 in the 4s orbital), and Ca's 20 protons attract the 4s electrons more strongly than K's 19 protons. Ca2+ is smaller than K+. They both have 18 electrons, and Ca's 20 protons attract the electrons more strongly than K's 19 protons. tossup #8–atom sizes chemistry unit 6 review Which is the largest atom among the following? Cℓ, Ar, Se, Br Se bonus #8–atom sizes chemistry unit 6 review Rank the following four elements from smallest to largest and explain each comparison separately. Cℓ, Ar, Se, Br Ar < Cl < Br < Se Ar < Cl (both have a few valence electrons in the 3p orbital, but Ar has one more proton than Cl, causing more attraction) Cl < Br (both have 7 valence electrons, but Cl's are in the smaller 3p orbital while Br's are in the larger 4p orbital) Br < Se (as with Ar vs. Cl, Br has one more proton, thus it attracts their similar 4p valence electrons more strongly than Se does) tossup #9–electron configuration chemistry unit 6 review How will electrons be distributed in the p-orbitals of any element in the oxygen family? Because one electron will go into each orbital before any electrons pair, the four electrons in an oxygen family element's p orbital would be arranged: ↑↓ ↑ ↑ bonus #9–orbitals chemistry unit 6 review Describe how the four electrons in the p-orbitals of an oxygen family element behave in terms of the actual orbitals pictured below. Two electrons would randomly zip around inside both halves of one of the above orbitals. Each of the other orbitals would have one electron randomly moving through both halves of it. tossup #10–spectra chemistry unit 6 review Why are salts such as copper (II) nitrate and strontium chloride mixed with the gunpowder inside of fireworks? Cu flame test http://en.wikipedia.org/wiki/File:Flametest--Cu.swn.jpg Many metal cations give off distinctive colors of light when they are heated to high temperature in a flame or other reaction. [In this case, copper produces green light and strontium produces crimson red light.] bonus #10–spectra chemistry unit 6 review Describe the general process by which an atom produces a spectrum when heated or subjected to high voltage. an electron in the atom absorbs energy that electron rises to a higher-energy orbital later that electron returns to a lower-energy orbital the excess energy that the electron loses is transferred to a photon which carries the energy away as light (or other electromagnetic radiation) tossup #11–spectra Suppose that due to the transitions shown at right, an element emits a spectrum containing orange, violet, and green light and infrared radiation. Which of these is the green light? 6p to 3p is green Ranking these four from least to greatest energy: infrared (4p to 3p) orange (5p to 3p) green (6p to 3p) violet (7p to 3p) chemistry unit 6 review bonus #11–spectra Given that these electron transitions produce infrared, orange, green, and violet lines in the spectrum, what electron transitions should produce: red light? ultraviolet radiation? red from e.g. 5s or 4d to 3p (more energy change than IR, less than orange) UV from e.g. 7p to 2p (more energy change than violet) chemistry unit 6 review tossup #12–electron configuration chemistry unit 6 review What is the electron configuration of a neutral iodine atom? (You may use shortcut notation.) [Kr] 5s2 4d10 5p5 bonus #12–families and periods chemistry unit 6 review Write the neutral formula of the salt formed by reacting iodine with the alkaline earth metal in the same period. SrI2 tossup #13–first ionization energies chemistry unit 6 review Given that the first ionization energy for calcium (Ca) is 590 kJ/mol, make reasonable estimates of the first ionization energies of K and Mg. They should be in the order K < Ca < Mg. (The real values are 419, 590, and 738 kJ/mol, respectively.) bonus #13–successive ionization energies chemistry unit 6 review Given that the first ionization energy for calcium (Ca) is 590 kJ/mol, make reasonable estimates of the 2nd, 3rd, and 4th ionization energies of Ca. e.g. 590, 1200, 9000, and 12 000 kJ/mol Each will be larger than the one before, and the 3rd I.E. will be much higher than the first two. (This is because Ca has two valence electrons; I.E. is modest for the valence electrons but much higher for core electrons.) tossup #14–atom and ion size 3– Rank the sizes of Sb , smallest to largest. Te < Te2– < Sb3– chemistry unit 6 review Te, 2– and Te from bonus #14–valence electrons chemistry unit 6 review Concerning their valence electrons, identify what is similar about Se and Te and what is different about them. Both have six valence electrons arranged in an ns2np4 configuration. But Te has those six electrons in the 5s and 5p orbitals, which are larger and higher in energy than the 4s and 4p orbitals where Se's valence electrons are. tossup #15–electron configuration chemistry unit 6 review What is the electron configuration of bismuth, 83Bi? [Xe] 6s2 4f14 5d10 6p3 bonus #15–electron configuration chemistry unit 6 review What is the electron configuration of gold, 79Au (a) assuming that it “follows the rules” (b) given that it “breaks the rules” (a) [Xe] 6s2 4f14 5d9 (b) [Xe] 6s1 4f14 5d10 One electron has been “promoted” from 6s to 5d. tossup #16–electron configuration chemistry unit 6 review Identify the ion that is isoelectronic with neon and is: a) a chalcogen b) an alkali metal a) oxide, O2– b) sodium ion, Na+ bonus #16–electron configuration chemistry unit 6 review Write the neutral formula of the salt yttrium selenide and compare and contrast the sizes of the ions of which it is made. Y2S3; Y3+ is smaller than Se2– The expected ions are Y3+ and Se2– both of which have electron configuration [Kr]. The neutral salt is thus Y2S3, and the Y3+ ion (39 protons with 36 electrons) should be considerably smaller than and Se2– (which has only 34 protons for 36 electrons).