Question

Rank the elements Cr, Mn, and Na in stone samples from Notre Dame compared to stone from Amiens Cathedral as the best indicators for distinguishing the two types of stone (rated from best to worst).

(a) Cr, Mn, Na
(b) Mn, Cr, Na
(c) Na, Mn, Cr
(d) Mn, Na, Cr

Answer 1

Manganese and chromium are the best indicators for distinguishing the two types of stone due to their different colors in different oxidation states. The correct option is b) Mn, Cr, Na.

Step-by-step explanation:

To rank the elements Cr, Mn, and Na as the best indicators for distinguishing the two types of stone, we need to consider their properties. Chromium (Cr) and manganese (Mn) are transition metals, while sodium (Na) is an alkali metal. Transition metals often have different colors and can form complexes, while alkali metals are known for their reactivity.

Based on these properties, the best indicator would be (b) Mn, Cr, Na. Manganese and chromium can exhibit different colors in different oxidation states, which can help distinguish different types of stone. Sodium, on the other hand, is less likely to be a good indicator as it is highly reactive and less likely to be present in the stone samples.