1. 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

2. 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 J
11.25 J/(3.62 x J photon-1)= 3.1 x 1019 photons
12/10/2018

3. 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 d f
12/10/2018

4. 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 d f
n=4
n=3
n=1
n=2
2n2
12/10/2018

5. 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

6. 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. 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

8. Periodic Relationships Among the Elements
Chapter 8

9. When the elements were discovered
12/10/2018

10. Classification of the elements
12/10/2018

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

12. 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

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

14. 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

15. 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