Alkaline (adjective, “AL-kah-line”)
The word “alkaline” comes from the word alkali, which refers to salts of alkali metals. Alkali metal salts such as sodium bicarbonate — or baking soda — are always basic, and so alkaline can now be used to describe any chemical that is a base.
Both alkaline and alkali come from the Arabic word “al-qili.” This is the word for the ashes of saltwort plants. Once these plants are burned, their ashes produce a strong base. That base is the salt of the alkali metal potassium. When alkaline chemicals like these are mixed with oil or other fats, they form soap.
In a sentence
The right alkaline chemicals could help astronauts make soil-based concrete on Mars.