Question

lets say that some other tube of toothpaste contains calcite (calcium carbonate). calcite (calcium carbonate) has a hardness of 3. which is harder, calcite (calcium carbonate) or apatite? calcite (calcium carbonate) is harder apatite is harder question 40 2.22 pts how likely is it that you would scratch your teeth if you used toothpaste containing calcite (calcium carbonate)? very likely not very likely

Explanation:

First Question (Which is harder...):

In mineral hardness (Mohs scale), apatite has a hardness of 5, while calcite has a hardness of 3. A higher hardness value means a mineral is harder. Since 5 > 3, apatite is harder.

Tooth enamel has a hardness of about 5 (similar to apatite). Calcite has a hardness of 3, which is less than enamel's hardness. A material with lower hardness is less likely to scratch a harder material. So using calcite - containing toothpaste is not very likely to scratch teeth.

Answer:

B. Apatite is harder

Second Question (How likely to scratch teeth...):