According to moh's hardness scale, your fingernail would be rated as 2.5. juan and carol are trying to identify an unknown mineral. carol can scratch the mineral sample with her fingernail. juan and carol know the mineral must be one of these four choices.

based on the scratch test, the mineral is

a) apatite.
b) calcite.
c) gypsum.
d) pyrite.

Of the choices, the mineral is gypsum. Your fingernail, hardness 2.5, can scratch a mineral with a hardness that is less than 2.5. Of the answer choices, the only possible answer is gypsum.

The answer is C. gypsum

sulfur dioxide

explanation: acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. these substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain.