[Manjaro]

This is general but which of these elements come in three forms of allotropes:

argon
bromine
chlorine
fluorine
helium
hydrogen
iodine
nitrogen
oxygen
phosphorus ( I know this element comes in two, red and white)
sulfur

If anyone one has a general anwser id be happy thank you.

[Arkcon]

phosphorus ( I know this element comes in two, red and white)

Good, so you can take that one off the list.  What does allotrope mean?  Can you use the definition to remove any others?

[Borek]

phosphorus ( I know this element comes in two, red and white)

Not less then four.

Remember: library first, wiki/google second, ask on forums third! This is really pretty easy question, all you have to do is to read about these elements in any book - most likely encyclopedia will do.

[Arkcon]

phosphorus ( I know this element comes in two, red and white)

Not less then four.

Remember: library first, wiki/google second, ask on forums third! This is really pretty easy question, all you have to do is to read about these elements in any book - most likely encyclopedia will do.

Yeah, I noticed when I checked wikipedia, may new allotropes that I'd never heard of have been discovered, under extreme conditions.  In fact, what I thought was the answer, turns out to be wrong.  Pretty much this is a crappy question to ask, it's just checking to see if the student read the book and can spit back the (wrong) answer given.

However, my comment still stands.  If an allotrope is defined as a molecule made of differing numbers of same element, can Manjuro exclude several from the list?

[AWK]

sulfur

Not less than a dozen