Atom, Elements, Periodicity Review

of 5 Atom, Elements, Periodicity Review

The diagram shows the first ionization energies for the elements from Li to Ne. Briefly (in one to three sentences) explain each of the following in terms of atomic structure. (a) In general, there is an increase in the first ionization energy from Li to Ne. (b) The first ionization energy of B is lower than that of Be. (c) The first ionization energy of O is lower than that of N. (d) Predict how the first ionization energy of Na compares to those of Li and of Ne. Explain.

1993 D Account for each of the following in terms of principles of atom structure, including the number, properties, and arrangements of subatomic particles. (a) The second ionization energy of sodium is about three times greater than the second ionization energy of magnesium. (b) The difference between the atomic radii of Na and K is relatively large compared to the difference between the atomic radii of Rb and Cs. (c) A sample of nickel chloride is attracted into a magnetic field, whereas a sample of solid zinc chloride is not.

(d) Phosphorus forms the fluorides PF3 and PF5, whereas nitrogen forms only NF3.

Answer the following questions regarding light and its interactions with molecules, atoms, and ions.

a. The longest wavelength of light with enough energy to break the Cl-Cl bond in Cl2(g) is 495 nm. i. Calculate the frequency, in s-1, of the light. ii. Calculate the energy, in J, of a photon of the light. iii. Calculate the minimum energy, in kJ mol-1, of the Cl-Cl bond. b. A certain line in the spectrum of atomic hydrogen is associated with the electronic transition in the H atom from the sixth energy level (n = 6) to the second energy level (n = 2). i. Indicate whether the H atom emits energy or whether it absorbs energy during the transition. Justify your answer. ii. Calculate the wavelength, in nm, of the radiation associated with the spectral line. iii. Account for the observation that the amount of energy associated with the same electronic transition (n = 6 to n = 2) in the He+ ion is greater than that associated with the corresponding transition in the H atom. 1987 D Two important concepts that relate to the behaviour of electrons in atom systems are the Heisenberg uncertainty principle and the waveparticle duality of matter. (a) State the Heisenberg uncertainty principle as it related to the determining the position and momentum of an object. (b) What aspect of the Bohr theory of the atom is considered unsatisfactory as a result of the Heisenberg uncertainty principle? (c) Explain why the uncertainty principle or the wave nature of particles is not significant when describing the behaviour of macroscopic objects, but it is very significant when describing the behaviour of electrons. Page 2 of 5

1. An example of a metal which is ductile and 8. In the Rutherford scattering experiment, what did malleable is: Rutherford observe to happen to the beam of A. Au D. K particles that bombarded the thin piece of gold foil? B. Cd E. Na A. None of the particles were deflected C. Hg B. Only a few particles were deflected, but An atom has an atomic mass of 45 and an atomic 2. the deflection was large. number of 21. Select the correct statement(s) C. Most of the particles were slightly about its atomic structure: deflected A. The number of electrons is 24 D. Most of the particles were greatly B. The number of neutrons is 24 deflected. C. The number of protons is 24 9. Bases on these observations form the scattering D. The number of electrons and neutrons is experiment, what did Rutherford conclude? equal A. The positive part of the atoms is moving E. The number of protons and neutrons is very rapidly. unequal B. The positive charge is distributed 3. Select the most unreactive element: throughout the atom. A. Cl D. S C. The positive part of the atom is B. H E. Xe relatively small and heavy. D. The negative part of the atom is relatively C. Na small and heavy. The correct ranking of alkali metals from most 13 4. 10. If the frequency of ultraviolet light is 5.0 x 10 reactive to least reactive is: Hz, what is the energy of one quantum of this A. Be-Mg-Co-Sr-Ba radiation? B. Cs-Rb-K-Na-Li A. 8.0 x 1046 J C. 3.5 x 10-20 J C. F-Cl-Br-I12 B. 5.7 x 10-6 J D. 2.9 x 10-27 J

D. I-Br-Cl-F 11. If the wavelength of ultraviolet light is 125 nm, E. Li-Na-K-Rb-Cs what is the energy of one quantum of this radiation? (there was a typo on original!) Which of the following is NOT an isotope of Ca 5. A. 6.19 x 10-14 J C. 3.60 x 10-23 J 40 41 B. 1.59 x 10-18 J D. 9.24 x 10-40 J A. 20 X C.21 X 43 41 12. Which of the following electronic transitions B. 20 X D.20 X in a hydrogen atom would have the highest energy? A. 12 n = 4 to n=1 C. n = 2 to n=1 6. If the frequency is observed to be 1.00 x 10 Hz for a microwave signal, what is the wavelength of B. n = 4 to n=2 D. n = 4 to n=3 this radiation in centimeters? 13. Which of the following electronic transitions A. -4 3.00 x 10 C. 3.34 in a hydrogen atom would have the longest B. 3.00 x 10-2 D. 3340 wavelength? A. n = 4 to n=1 C. n = 2 to n=1 7. Which of the following has the longest wavelength? B. n = 4 to n=2 D. n = 4 to n=3 A. Blue light C. ultraviolet 14. Calculate the energy change associated with B. Visible D. Radar the third line of the Balmer Series for hydrogen Page 3 of 5 gas, that is, the transition resulting when an 23. Which of the following is NOT a valid set of electron moves from n=5 to n = 2. quantum numbers? A. -276 KJ/mol C. -486 KJ/mol A. n = 4, l =0, ml = -1 (ml can only be B. -394 KJ/mol D. -700 KJ/mol zero) 15. When n = 3, which of the following is a B. n = 6, l =5, ml = 0 possible value for l? (l – all integral C. n = 2, l =1, ml = +1 values zero to n-1) D. n = 3, l =2, ml = -2 A. -1 B. 0 C. 3 D. 6 24. For a certain orbital, n = 4, l =1, ml = -1. 16. When l = 2, which of the following is a What type of orbital is this? A. possible value for ml ? (all integral values 3p C. 4p (l = 0,1,2 is s,p,d – l to + l) resp) A. -3 B. 1 C. 3 D. 4 B. 4s D. 4d 17. When l = 2, what is the maximum number of 25. If an electron subshell has 9 orbitals, what is orbitals of this type possible in a given electron the l value for this subshell? (9 orb, f sublevel, l shell (i.e. for a particular n value)? ( l = 2 is d) = 3) A. 3 B. 5 C. 7 D. 9 A. Two C. four 18. When l = 2, what set of orbitals is designated? B. Three D. five A. p B. d C. f D. g 26. Electron spin is quantized in such a way that, 19. What name is given to a region of an electron in an external magnetic field, ____ orientations of probability density graph where the probability of the electron spin are possible. (+1/2 and -1/2) finding the electron is zero? A. One C. three A. Node C. wave function B. Two D. the # is not definite B. Orbital D. Lobe 27. What is the maximum number of electrons that 20. The lowest-energy stationary state of an atom can be placed in a 5f orbital?( orbital not is called its______. sublevel!) A. Wave function C. ground state A. Two C. fourteen B. Node D. orbital B. Eight D. eighteen 21. Each quantum mechanical wave function does 28. What noble gas symbol would be used for the not have a readily interpretable physical meaning, noble gas configuration for the element platinum? the the square of the wave function gives the A. [Ar] C. [Xe] ______of finding the electron at a certain point. B. [Kr] D. [Rn] A. Bohr orbital C. energy Write the electron configurations for the B. Probability D. velocity 29. following (be careful!): 22. According to Heisenberg’s uncertainty A. Se: 1s22s22p63s23p64s23d104p4 principle, if one attempts simultaneously to B. I: 1s22s22p63s23p64s23d104p65s24d105p5 measure the position and momentum of an electron, the more exactly the position is measures, C. Cu: 1s22s22p63s23p64s13d10 (anomaly!) the greater will be the ______in the D. 2 2 6 2 6 1 5 Cr: 1s 2s 2p 3s 3p 4s 3d (anomaly!) momentum measurement. E. 2 2 6 2 6 2 10 6 2 A. Value C. Uncertainty Sr: s 2s 2p 3s 3p 4s 3d 4p 5s B. Probability D. energy 30. Draw orbital diagrams for the following: A. P (see end) Page 4 of 5 B. Mo D. F- < O2- < Na+ C. Sn 39. An element having which of the following 31. Which one(s) of the above are paramagnetic? electronic configurations would have the greatest All ionization energy? A. [He]2s22p3 32. Which of the following ions is diamagnetic? B. 2 5 A. Ti2+ C. V2+ [He] 2s 2p C. 2 3 B. Mg2+ D. Cr2+ [Ne]3s 3p D. [Ne]3s23p5 33. Which of the following elements has two unpaired electrons when it is a +3 ion? 40. Periodic trends: A. Vanadium C. Cadmium A. Which should be larger, the oxide ion, O2-, B. Aluminum D. Antimony or the oxygen atom? O2- B. Which type of element below has atomic sizes Which should have the largest difference 34. st nd that remain almost identical across a period? between the 1 and 2 ionization energy? O, S, or Se Oxygen A. Main group metals B. Main group nonmetals C. Transition metal elements D. None of these 35. Which of the following groups of elements is arranged correctly in order of increasing first ionization energy? A. Mg < C < N < F B. N < Mg < C < F C. Mg < N < C < F D. F < C < Mg < N 36. Which of the following groups of elements is arranged correctly in order of decreasing atomic radius? A. Mg < S < Al < Cl B. Al < Mg < S < Cl C. Mg < Al < S < Cl D. Cl < S < Mg < Al 37. Which of the following elements would have the greatest difference between the first and the second ionization energy? A. Li B. C C. F D. N 38. Which of the following groups of ioselectronic species show the elements arranged correctly in order of increasing size? A. Na+ < O2- < F- B. F- < Na+ < O2- C. Na+ < F- < O2- Page 5 of 5

ORBITAL DIAGRAMS:

P:  ____ ____ ____  ____ ____ ____ ____ ____  ____ 1s 2s 2p 3s 3p

      Mo: [Kr] ______5s 4d         Sn: [Kr] ______5s 4d 5p