8. The tape for sealing pipe joints is generally made of
A. ABS
B. Teflon
C. PVC
D. epoxy resin

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9. The energy required to liberate an electron from an atom is called
A. kinetic energy
B. potential energy
C. excitation energy
D. ionization energy

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10.  A germanium atom contains
A. 2 orbiting electrons
B. two protons
C. four valence electrons
D. six valence electrons

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11. A silicon atom contains
A. 2 valence electrons
B. 2 protons
C. 4 valence electrons
D. 6 valence electrons

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12.  The valence electrons are
A. free electrons
B. outer orbit electrons
C. inner core electrons
D. located in the nucleus

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13.  In n-type germanium, each donor atom contributes.
A. one free electron
B. 2 free electrons
C. free electrons
D. 3 free electrons

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14.  In n-type silicon, each donor atom contributes
A. one free electron
B. 2 free electrons
C. 3 free electrons
D. 4 free electrons

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