Solutions Set 1 E-344
Due: Tuesday, 26 January, Spring 2010
1. Core 2.03 number of atoms a silicon wafer
a) The volume of the single-crystal Si wafer:
The mass of the wafer:
The mole of Si atoms:
The number of Si atoms:
b) Atomic fraction of P in Si:
2. Core 2.05 number of sodium atoms and the estimated the size of a single sodium
atom
a) The volume of the Na cube:
The mass of the Na cube:
The mole of Na atoms:
The number of Na atoms:
b)
ASSUMPTION 1:
Assuming the sodium atoms are arranging as close-packed spheres in BCC crystal
structure, then:
The volume of the unit cell:
There are 2 atoms in the unit cell.
Atomic packing factor (APF) =
The total real occupied volume of Na atoms:
The volume of a single Na atom: The radius of Na atom: Almost the same as the value tabulated in the textbook.
ASSUMPTION 2:
If you didn't know the crystal structure, you could assume that each atom has the shape of
a small cube. Then, the volume per atom should be:
The edge length per atom cube:
The radius of Na atom:
, slightly deviated from the value tabulated.
3. Callister 2.6 quantum numbers and spdf notation
For the L state, n = 2, and eight electron states are possible. Possible l values are 0 and 1,
while possible ml values are 0 and ±1; and possible ms values are ±12. Therefore, for the
s states, the quantum numbers are 200(1/2) and 200(−1/2). For the p states, the quantum
numbers are 210(1/2), 210(−1/2), 211(1/2), 211(−1/2), 21(−1)(1/2), and 21(−1)(−1/2).
For the M state, n = 3, and 18 states are possible. Possible l values are 0, 1, and 2;
possible ml values are 0, ±1, and ±2; and possible ms values are ±1/2. Therefore, for the s
states, the quantum numbers are 300(1/2), 300(−1/2), for the p states they are 310(1/2),
310(−1/2), 311(1/2), 311(−1/2), 31(−1)(1/2), and 31(−1)(−1/2); for the d states they are
320(1/2), 320(−1/2), 321(1/2), 321(−1/2), 32(−1)(1/2), 32(−1)(−1/2), 322(1/2), 322(−1/2),
32(−2)(1/2), and 32(−2)(−1/2).
4. Callister 2.7 spdf electron configurations for various ions.
P5+: 1s22s22p6
P3-: 1s22s22p63s23p6
Sn4+: 1s22s22p63s23p63d104s24p64d10
Se2-: 1s22s22p63s23p63d104s24p6
I-: 1s22s22p63s23p63d104s24p64d105s25p6
Ni2+: 1s22s22p63s23p63d8
5. Core 2.12 spdf notation and electronegativity of chlorine
Cl(17)=1s2 2s2 2p6 3s2 3p5
Chlorine has a relatively high electronegativity, i.e. the degree to which an atom attracts
an electron, because
Adding another electron to Cl will completely fill the 3p shell. Fully filled electron shells
are relatively stable.
6. Core 2.13 planetary model and energy-level diagram for chlorine
Planetary Model
Energy Level Diagram
7. From Summer 2009 Midterm: The atomic number of magnesium (Mg) is 12.
A) Mg: 1s22s22p63s2
B)
C)
D)
8. Callister 2.18 primary bonding and Pauli
a) The main differences between the various forms of primary bonding are:
Ionic--there is electrostatic attraction between oppositely charged ions.
Covalent--there is electron sharing between two adjacent atoms such that each atom
assumes a stable electron configuration.
Metallic--the positively charged ion cores are shielded from one another, and also "glued"
together by the sea of valence electrons.
b) The Pauli exclusion principle states that each electron state can hold no more than two
electrons, which must have opposite spins.
9. Callister 2.23 HF and HCl dipole strength
The intermolecular bonding for HF is hydrogen, whereas for HCl, the intermolecular
bonding is van der Waals. Since the hydrogen bond is stronger than van der Waals, HF
will have a higher melting temperature.