In the periodic table Platinum is 195.084 under solids.
If you would weigh an ounce of Platinum on a scale
Could you identify the metal just by the weight alone?

Trick question, as it would WEIGH an ounce...
So no..

Guess it depends on the scale. Elements I think have a atomic weight
Thanks

They do but its based differently... an ounce is an ounce no matter what you weigh. Balsa wood or lead. Because an ounce is a predefined weight, what will vary is the volume and density from one material to the next.

If I gave you two pieces of metal. Lets say one was lead
And the other was platinum. What would you do to find the identity.

This is now a better question. Obviously weight alone is not sufficient (like the old trick question for 5 -year olds: which weighs more, a pound of rocks or a pound of feathers?). But if you can measure the object's volume and its weight then you can calculate its density. If the choice is strictly between lead and platinum the platinum sample will have a higher density. Or you could measure its electrical conductivity - platinum is a good conductor whereas lead is not. Or test its hardness - Pb is relatively soft.

There is also a modern shortcut... based on something I was part of a design team on back in 1993 (they existed before then...just not mid price range ones). Place a sample in a scanning electron microscope that's hooked to a mass spectrometer. Not as much to learn that way versus doing it the old fashioned way however. Not to mention very few people would have a clue where to even find one.

Density . Almost like gold or silver are not magnetic metals.

Density is unrelated to magnetic properties. There are both much less dense, and far more dense elements that are non-magnetic. In fact, (ebaines will correct me if I'm wrong). Of all of them, I believe only Iron has magnetic properties.

Iron, nickel, and cobalt are the three elements ferromagnetic at room temperature. Gadolinium and Dysprosium are ferromagnetic below room temperature.

Read the link
The Golden Crown (Introduction)

In conclusion would you said a density test would determine the identity of the solid element. Or perhaps a series of test. Since it seems that the atomic weight alone doesn't fulfill the identity requirement.