7.85 The electron configuration of a neutral atom is 1s22s22p63s2. Write a complete set of quantum numbers for each of the electrons. Name the element. 1s: n=1, l=0, ml=0, ms= +1/2 or -1/2 2s: n=2, l=0, ml=0, ms= +1/2 or -1/2 2p: n=2, l=1, ml=-1, 0, and 1, ms= +1/2, or -1/2 3s: n=3, l=0, ml=0, ms= +1/2 or -1/2 Mg 12/10/2018

7.104 Only a fraction of the electrical energy supplied to a tungsten lightbulb is converted to visible light. The rest of the energy shows up as infrared radiation (heat). A 75-W lightbulb converts 15.0% of the energy supplied to it into visible light (assume the wavelength to be 550 nm). How many photons are emitted by the lightbulb per second? (1 W = 1 J/s) 1 photon = 3.62 x 10-19 J 11.25 J/(3.62 x 10-19 J photon-1)= 3.1 x 1019 photons 12/10/2018

7.61 Calculate the total number of electrons that can occupy (a) one s orbital, (b) three p orbitals, (c) five d orbitals, (d) seven f orbitals. s 2 p 6 d 10 f 14 12/10/2018

7.62 What is the total number of electrons that can be held in all orbitals having the same principal quantum number? s 2 p 6 d 10 f 14 n=4 n=3 n=1 n=2 2n2 12/10/2018

7.57 Discuss the similarities and differences between a 1s and a 2s orbital. Both have a spherical shape 2s orbital is larger 1s orbital is lower in energy Harder to remove a 1s electron 12/10/2018

7.81 The atomic number of an element is 73. Is this element diamagnetic or paramagnetic? paramagnetic If an element has an odd number of electrons, it is paramagnetic. If an element has an even number of electrons, it may be either paramagnetic or diamagnetic. 12/10/2018

7.92 Use the Aufbau principle to obtain the ground state electron configuration of technetium. Technetium= Tc= 43 Tc= [Kr]5s24d5 Indicate one possible excited state configuration. Draw an orbital energy diagram for the ground state and your excited state. 12/10/2018

Periodic Relationships Among the Elements Chapter 8

When the elements were discovered 12/10/2018

Classification of the elements 12/10/2018

Ground state electron configurations of the elements ns2np6 ns1 ns2np1 ns2np2 ns2np3 ns2np4 ns2np5 ns2 d10 d1 d5 4f 5f 12/10/2018

Electron configurations of cations and anions (representative elements) Atoms lose electrons so that cation has a noble-gas outer electron configuration. Na [Ne]3s1 Na+ [Ne] Ca [Ar]4s2 Ca2+ [Ar] Al [Ne]3s23p1 Al3+ [Ne] H 1s1 H- 1s2 or [He] F 1s22s22p5 F- 1s22s22p6 or [Ne] Atoms gain electrons so that anion has a noble-gas outer electron configuration. O 1s22s22p4 O2- 1s22s22p6 or [Ne] N 1s22s22p3 N3- 1s22s22p6 or [Ne] 12/10/2018

Cations and anions of representative elements +1 +2 +3 -3 -2 -1 12/10/2018

Na+, Al3+, F-, O2-, and N3- are all isoelectronic with Ne Na+: [Ne] Al3+: [Ne] F-: 1s22s22p6 or [Ne] O2-: 1s22s22p6 or [Ne] N3-: 1s22s22p6 or [Ne] Na+, Al3+, F-, O2-, and N3- are all isoelectronic with Ne What neutral atom is isoelectronic with H- ? H-: 1s2 same electron configuration as He 12/10/2018

8.80 Arrange these species in isoelectronic pairs: O+, Ar, S2-, Ne, Zn, Cs+, N3-, As3+, N, Xe. O+, N Ar, S2- Ne, N3- Zn, As3+ Cs+, Xe 12/10/2018