Cliffs AP Chemistry, 3rd Edition

(singke) #1

  1. Choose the one FALSE statement.
    A. Nuclei with an even number of protons and an even number of neutrons tend to be
    stable.
    B. “γ”-rays are high-energy photons.
    C. Nuclei with too few neutrons per proton tend to undergo positron (^01 b) emission.
    D. Light nuclides are stable when the atomic number (Z) equals the mass number
    minus the atomic number (A–Z).
    E. Nuclei with too many neutrons per proton tend to undergo β-particle (- 10 e) emission.


Answer: E


Positron production occurs for nuclides that are below the zone of stability (those nuclides
whose neutron/proton ratios are too small). The net effect of positron emission is to change a
proton to a neutron. An example of positron emission would be


(^2211) Na" (^01) e+ (^2210) Ne
Nuclides with too many neutrons per proton tend to undergo β-particle production. The net
effect of β-particle production is to change a neutron to a proton. Examples of β-particle
production are
(^23490) Th" (^23491) Pa+- (^01) e
(^13153) IXee" (^13154) +- (^01)
Questions 5–9
A.^20180 Hg++-^01 e"^20179 Au^00 c
B.^116 CeB"^01 +^115
C.^23793 Np"^42 He+^23391 Pa
D.^23592 U+++ 01 n"^14156 Ba^9236 Kr 310 n
E.^21483 Bi"^21484 Po+-^01 e



  1. Alpha (α)-particle production.


Answer: C


An alpha particle is a helium nucleus.


Part II: Specific Topics

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