Question

which of the following pairs represent isotopes? a: (^{28}\text{si}) and (^{28}\text{si}^{4 +}) b: (^{28}\text{si}) and (^{28}\text{al}) c: (^{28}\text{si}) and (^{29}\text{si}) d: (^{28}\text{si}) and (^{28}\text{si}^{4 -}) e: (^{28}\text{si}^{4+}) and (^{28}\text{al}^{3 +})

Explanation:

Isotopes are atoms of the same element with different mass - numbers due to varying numbers of neutrons. Option C consists of \(^{28}Si\) and \(^{29}Si\), which are both silicon atoms but with different mass - numbers (28 and 29 respectively). In option A, one is an ion (\(^{28}Si^{4 +}\)) and the other is an atom. In option B, they are atoms of different elements (Si and Al). In option D, one is an ion (\(^{28}Si^{4-}\)) and the other is an atom. In option E, they are ions of different elements (Si and Al).

Answer:

C. \(^{28}Si\) and \(^{29}Si\)