do compounds with the same elements create the same substances

Question

structure of matter worksheet, Accelerate learning

 

Answer 1

Even if present in the same amounts they can be different. These are known as structural isomers. An isomer is a molecule with the same molecular formula as another molecule, but with a different chemical structure. An example would be propanol and isopropanol. Both are C3H8O.  Elements are in the same amounts but they are different compound. So, the answer to your question is clearly NO. 

Answer 2

They will only create the same substances if the elements are in the same amounts in the chemical formula.

 

Take a look:

 

One carbon with four hydrogen atoms attached will give you the smelly gas methane. It's formula looks like this:

 

CH₄

 

Three carbon atoms with eight hydrogen atoms attached will give you propane. A different gas entirely. That looks like this:

 

C₃H₈

 

Both compounds are made up of the same elements (atoms) but are different substances.