What type of compounds do not contain carbon?

Inorganic compounds are characterized by their lack of carbon-hydrogen (C-H) bonds. This distinct absence sets them apart from organic compounds, which are primarily based on carbon and can contain hydrogen along with other elements such as oxygen, nitrogen, sulfur, and phosphorus. Examples of inorganic compounds include salts, minerals, and metals.

In contrast, ketones and aldehydes are both classes of organic compounds. They contain carbon and are defined by specific functional groups involving carbon atoms. Since organic chemistry focuses on the study of compounds primarily made up of carbon, these two options do not fit the criterion of containing no carbon.

The term "organic compounds" explicitly refers to those compounds that predominantly contain carbon. Therefore, it is clear that inorganic compounds are the correct answer since they define compounds that do not include carbon in their structure. This distinction is crucial in chemistry, particularly when differentiating between the varying types of substances based on their elemental composition.