Which mineral will scratch fluorite, galena, and pyroxene?

Which of the following statements about c4 carbon fixation is not true? a c4 carbon fixation is an adaptation for plants exposed to high light intensityb. c4 carbon fixation occurs in more plants than c3 carbon fixation.c c4 carbon fixation is more common in areas of high temperatures than c3 carbon fixation.d. c4 carbon fixation occurs in the inner cells of a leaf rather than the entire leaf.

1) what three conditions must be present for minerals to form through natural processes? 2) why are minerals considered inorganic substances? 3) how do oxides differ from other minerals that contain oxygen atoms? 4) how is a sulfide different from a sulfate? what makes native elements unique?

What are the student's observations and inferences before he starts his investigation?