No, "downstream" is not a compound word. It is a single word that combines the words "down" and "stream" to refer to the direction in which a river or stream flows.
compound words
Sodium acetate is a compound. Generally, when the name of a substance contains two or more words (unless one of them is solid, liquid, gas, or metal), it is not an element.
Yes, into and today are compound words.
Compound words that have when in them are whence, whenever, and whensoever.
No, if they are separate words they are not compound.
compound words written as two
Some compound words that have "oil" in them are: oilcloth, oilrig, oilcan, oilskin.
circus, circuit, circular, circulation, circulated, circumstances, circumstance, circulate, circumference, circumspect, circumstantial
Compound words can be made with almost any two words.
Compound words with sand:SandbagSandbankSandbarSandblastSandboxSandburgSandcastleSandhogSandlotSandlotterSandmanSandmenSandpaperSandpiperSandpitSandstoneSandstormSandwichCompound words ending with sand:Quicksand
Compound words with "Thing":AnythingBirthingClothingEarthingFaithingFarthingGirthingKithingLathingLoathingLocksmithingMouthingNorthingNothingPithingPlaythingSmithingSomethingSoothingTithingUnderclothingWithingWorthingWrathing