All around us are natural or artificial compounds (excepting elements).
Yes, "useful" is a compound word made up of the root word "use" and the suffix "-ful" which means "full of."
water
family
Carbon tetrachloride, a useful but toxic solvent.
like in pools, it keeps em clean ;]
For example the melting point.
A compound miter saw can cut two angles at the same time. Very useful when cutting crown molding.
Sulfur dioxide is the name of the compound with the chemical formula SO.
Compound as it does have a unneeded ending. "and is quite useful". Meaning that the sentence does make sense with out that part of the sentence. If it didn't have this extra bit it would be a simple sentence.
Because they are useful.
The maximum useful magnification of a compound light microscope is typically around 1000x. Beyond this point, image quality decreases due to limitations in the lens quality, resolution power, and diffraction of light.
Examples: methane, starch, sucrose, ethanol, oil, greases, dyes, etc.