Critique the following statement made by a student looking at a TEM image of dolomite. "The TEM image shows regular patterns of small dots, large dots, and tiny dots. The formula for dolomite is CaMg[CO3]2. I think the large dots must be the carbonate groups."
A) The student is correct.
B) The student is probably correct because four atoms will make a larger mark than one atom.
C) The student is probably incorrect because the single metal atoms have a denser arrangement of electrons than the carbonate group.
D) The student is incorrect because the image must not be dolomite. Since there are four types of atoms, the TEM for dolomite should have four sizes of dots.

Question

Quizplus · Accepted Answer

The student's assumption that the large dots represent the carbonate groups in the dolomite molecule is likely incorrect because individual metal atoms have a denser arrangement of electrons than the carbonate group. Therefore, it is more likely that the small dots represent the metal atoms, while the larger dots could be the oxygen atoms in the carbonate group. However, it is also important to consider that TEM images are not always definitive and could potentially show other structures or artifacts that may not be related to the dolomite molecule.

Critique the Following Statement Made by a Student Looking at a TEM