56. A Ge atom contains :
(a) Four valence electrons
(b) Six valence electrons
(c) Four protons
(d) Six protons
57. Valence electrons are found :
(a) In the nucleus
(b) In the innermost shell
(c) In the outermost shell
(d) As free electrons in an atom
58. When an atom loses one electron :
(a) It becomes positive ion
(b) It becomes negative ion
(c) It becomes neutral
(d) It also loses one proton
59. Seed crystal used in crystal growth is :
(a) A small crystal formed out of epitaxial growth
(b) A signal crystal with a specific orientation
(c) A signal crystal containing acceptor impurity
(d) A signal crystal containing donor impurity
60. Crystal structure possessing imperfection causes :
(a) Increased mobility
(b) Decreased mobility
(c) Increased conductivity
(d) Decreased conductivity
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