Examine the spectra of the four unknown substances shown below. what can you conclude? substances w and y are the same. substances x and z are the same. all of the substances are from the same sample. none of the substances are the same.

Line spectra are obtained when individual elements are heated using a high-voltage electrical discharge. This heating causes excitation of the element and a subsequent emission of distinct lines of colored light are obtained. Each element has its own unique emission line spectrum; therefore, if any of the tested substances were the same, their spectra would match. However, this is not the case so none of the substances are the same.
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Substances X and Z are the same.

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