Diamonds are one of the hardest materials known. Hardness is how resistant a material is to being scratched by another material. If two samples of metal that appear identical
are scratched by a diamond, is that sufficient to determine that they are the same metal?
Why or why not?

Which factor is likely to impact the possible number of compounds? presence of unlimited number of elements in the periodic table the inability of atoms to align perfectly with other atoms the ability of all elements to react with every other element all elements being equally reactive