What type of chemical is Lithium, which is currently undergoing research to prevent Alzheimer's?

Lithium is classified as an element because it is a pure substance that consists entirely of one type of atom, characterized by its atomic number 3 on the periodic table. As an elemental form, it exists in a solid state at room temperature and displays distinct physical and chemical properties, such as being highly reactive and flammable when exposed to water or air.

In the context of Alzheimer's research, lithium's potential neuroprotective effects are being studied. Scientific investigations are focused on how lithium might stabilize mood and cognitive function, which has implications for neurodegenerative conditions. The other options, such as compounds, mixtures, or salts, involve combinations of different elements or molecules, which do not accurately describe lithium's single-atom structure. Thus, recognizing lithium as an element is crucial for understanding its fundamental properties and potential therapeutic effects in health research.