How can you tell from one element from another?

Answer 1

The best way to tell elements from each other is to test their physical properties. Density and reactivity are excellent properties to test to tell elements apart.

Answer 2

If you have a sample of the pure element, the physical properties (melting point, color, crystal form) will usually give you a pretty good idea.

Another very good way is spectrographic: each element has a distinctive "spectral fingerprint" and indeed often the color of the flame itself is enough to give you a very strong clue what element you have.

Finally, there's good old fashioned qualitative analysis, which involves taking a sample and reacting it with various reagents to see when it forms a precipitate. For example, if adding hydrochloric acid forms a precipitate, then you've probably got lead, silver, or Mercury, and a few additional tests will tell you which. If it doesn't precipitate with hydrochloric acid but does with hydrosulfuric acid, then it's one of a different set (and more testing will again tell you which) If that didn't do it but something precipitates when you make the solution basic, then you've got one of yet another set, and so on.

If you'd like to know the exact steps involved, many college freshman chemistry texts include a section on qualitative analysis; my own college used Whitten & Gailey's General Chemistry with Quantitative Analysis, which had a fairly extensive section on the topic.

Answer 3

The best way to tell elements from each other is to test their physical properties. Density and reactivity are excellent properties to test to tell elements apart.

Answer 4

how can u they never touch each other