What properties would you look for to find out if an object is made of metal?

Answer 1

A water displacement test can determine the volume of the object. Next the object needs to be weighed. The mass to volume ratio will give you the density of the object. Provided that the object is not hollow and that the object is homogenous, you should be able to determine what type of metal the object is made out of strictly based upon the density. Metal color and general qualities (dull/shiny) as well as a simple magnetic test can also further narrow down the metal type. Taking a sample of the object and running it through a mass-spectrometer can give you the exact elemental composition of the metal.

Answer 2

One method is the flame test.

For somebody not in a laboratory setting, you can usually figure out what type of metal something is generally with just a magnet!

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That is hardly helpful beyond sorting scrap! All it does is indicate the metal is magnetic - principally iron and steels with the exceptions of most stainless-steel grades, but not which type of steel alloy.

Colour of cut or polished surface is a good guide for some common metals.

Copper has a distinctive deep golden colour, but so have some of its alloys such as Gilding Metal and Phosphor Bronze. Brass is yellowish - an alloy called Aluminium Bronze is similar but paler and more silvery. Aluminium and lead have silvery sheens, but lead oxidises to a uniform mid-grey.

The flame test works to a point, but unless you really know the flame colours or have a spectroscope and table of flame colours to hand, almost the only common metal it will indicate with any attempt at accuracy is copper (green flame). Lead would melt - as would aluminium if heated too enthusiastically! Nearly all the common metals give yellowish flames.

Acid etching of polished and cleaned surfaces can help comparative tests to differentiate between similar alloys. I noticed this effect when cleaning a small assembly I had sectioned, in which a core component I knew was turned from drawn brass, etched to a distinctly paler shade than the cast brass or gun-metal outer part. This is only of use as an identifier if you have control samples of known composition to test and compare to the specimens.

Density or specific gravity is a good way, assuming small enough test-pieces, a sufficiently sensitive balance, book of metal properties; and of course it is non-destructive.

Answer 3

In order to identify metals, testing on their properties comes in handy. On heating, metals will have high melting and boiling points. At the same time, materials that conduct heat and electricity are most likely to be metals.

Answer 4

"see if a magnet sticks to it, if it does it is metallic"

Wrong..... Not all metals are metallic. You could run an electric current through it to test for metals.

Answer 5

Perhaps trying to run an electric current through the material or placing it in an electrolyte solution and passing a current through that.

Answer 6

Density, forms ionic bonds with nonmetals, conducts electricity, occasional magneticity