Question

which transition metals are paramagnetic but can easily form ferromagnetic alloys with other metals?
a) transition metals in groups 8 - 10, periods 4 and 5
b) transition metals in groups 8 - 10, periods 5 and 6
c) transition metals in groups 1 - 5, periods 5 and 6
d) transition metals in groups 11 and 12, periods 4 and 5
question 20 (5 points)
which type of semiconductor is created by doping with atoms that contain more valence electrons than the semiconductor material?
a) n - type
b) intrinsic and p - type
c) intrinsic

Explanation:

• For the first question: Transition metals in groups 8 - 10 (such as Fe, Co, Ni in period 4 and Ru, Rh, Pd in period 5) are paramagnetic in their pure form but can form ferromagnetic alloys.
• For the second question: In N - type semiconductors, doping is done with atoms that have more valence electrons (e.g., doping Si with P). The extra electrons become free to conduct electricity.

Answer:

1. A. Transition metals in groups 8 - 10, periods 4 and 5
2. A. N - type