Identify the pairs which are not of isotopes.
a. \(_{6}^{12}X \ , \ _{6}^{13}Y\)
b. \(_{17}^{35}X \ , \ _{17}^{37}Y\)
c. \(_{6}^{14}X \ , \ _{7}^{14}Y\)
d. \(_{4}^{8}X \ , \ _{5}^{8}Y\)
1. a, d
2. b, c
3. c, d
4. b, d
a) ¹²₆X and ¹³₆Y have the same atomic number but different mass numbers; therefore, they are isotopes.
(b) ³⁵₁₇X and ³⁷₁₇Y have the same atomic number but different mass numbers; therefore, they are isotopes.
(c) ¹⁴₆X and ¹⁴₇Y have different atomic numbers but the same mass number; therefore, they are isobars.
(d) ⁸₄X and ⁸₅Y have different atomic numbers but the same mass number; therefore, they are isobars.
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