Atomic number |
78 |
77 |
76 |
46 |
45 |
44 |
Atomic weight |
195.23 |
193.1 |
190.2 |
106.7 |
102.91 |
101.7 |
Lattice structure |
F.c. cube |
F.c. cube |
C.p. hex |
F.c. cube |
F.c. cube |
C.p. hex |
Lattice constants, a |
3.92 |
3.83 |
2.72 |
3.88 |
3.80 |
2.70 |
c |
— |
— |
4.314 |
— |
— |
4.27 |
Density at 20°C |
21.4 |
22.4 |
22.5 |
11.9 |
12.4 |
12.3 |
Melting point, °C |
1769 |
2442 |
>2550 |
1552 |
1960 |
> 2550 |
Thermal conductivity, C.G.S. units |
0.17 |
0.35 |
— |
0.17 |
0.36 |
— |
Specific heat, cal/gm/°C at 20°C |
0.032 |
0.032 |
0.031 |
0.058 |
0.059 |
0.031 |
Coefficient of linear expansion (0-100°C) |
8.9 × 10−6 |
6.5 × 10−6 |
6.6 × 10−6 |
11.7 × 10−6 |
8.5 × 10−6 |
9.6 × 10−6 |
Resistivity, microhm-centimetres at 20°C |
10.6 |
5.3 |
9.5 |
10.7 |
4.7 |
9.5 |
Temperature coefficient of resistance (0-100°C) |
0.0039 |
0.004 |
0.0042 |
0.0038 |
0.0046 |
0.0042 |
Mass susceptibility |
+1.10 × 10−6 |
+0.15 × 10−6 |
+0.05 × 10−6 |
+5.4 × 10−6 |
+1.11 × 10−6 |
+0.50 × 10−6 |
Thermionic functions, A, amp. cm−2(°K)−2 |
32 |
— |
— |
60 |
33 |
— |
ø, volts (work function) |
5.32 |
5.40 |
— |
4.99 |
4.80 |
— |
Tensile strength—annealed—tons/in2 |
10 |
16 |
— |
10 |
24 |
— |
Limit of proportionality — annealed—tons/in2 |
2 |
— |
— |
2 |
— |
— |
Elongation—annealed—per cent |
40 |
— |
— |
40 |
5 |
— |
Modulus of elasticity in tension, lb/in2 |
22 × 106 |
74 × 106 |
— |
16 × 106 |
40 × 106 |
— |
Hardness—annealed—V.P.H. |
40 |
220 |
350 |
40 |
100 |
240 |