Why does hematite cause the rusty red color observed in many surface rocks?
A) Hematite is a carbon-oxide, giving rocks the red color (even if in small amounts).
B) Hematite contains pyrite, giving rocks the red color (even if in small amounts).
C) Hematite is an iron-oxide, giving rocks the red color (even if in small amounts).
D) Carbonic acid weathers hematite, giving rocks the red color (even if in small amounts).
Question 2
Why is carbonic acid the most abundant acid in chemical weathering?
A) Carbon dioxide is present in the atmosphere and in soil; it combines with water vapor in the atmosphere and water percolating through soil to produce weak carbonic acid.
B) Carbon dioxide easily breaks down to carbonic acid.
C) Carbonic acid is so good at chemical weathering that it appears all the time.
D) Acetic acid is rare, so carbonic acid is common.
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