I think the answer is a pure substance
Tollen's test is an organic test that determines whether the sample is an adehyde or not. When aldehydes are present, the reaction forms a silver compound which refers to the other name of Tollen's as silver mirror test. The aldehyde among the choices is C. pentanal
The process by which rocks are broken down to form soil is called weathering. It is divided into 3 types, physical, chemical and biological weathering.
Physical weathering is the process by which rocks are broken down as a result of physical agitations. It is also called mechanical weathering and during this process the chemical nature of the rock is not affected. Biological weathering has to do with the weakening of rocks and their eventual disintegration as a result of plants and animals activities. Chemical weathering refers to the disintegration of the rock particles as a result of chemical reactions.
