How did the later discovery of isotopes explain why ordering by atomic mass sometimes gave the wrong sequence?

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Question

How did the later discovery of isotopes explain why ordering by atomic mass sometimes gave the wrong sequence?

Accepted Answer

Relative atomic mass depends on the mixture of isotopes present, not simply on proton number — Award 1 mark. An element with a large share of heavy isotopes can therefore have a greater relative atomic mass than the element that follows it.

Answer

Isotopes have no measurable mass

Answer

Isotopes of an element have different numbers of protons

Answer

Relative atomic mass depends on the mixture of isotopes present, not simply on proton number

Answer

Isotopes of an element react in completely different ways

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