[alancalverd]

A stationary electron actually has three dimensions, which is why I opted for a π orbital which definitely has charge but according to Schrodinger it's kinda smeared out so it's nowhere in particular at any time.

Wikipedia gives a neat physicist's description

A metal conducts electricity at a temperature of absolute zero, which is a consequence of delocalized states at the Fermi energy.

even if it's a bit idealised. But then

iodine gradually becomes a metal at a pressure of between 40 and 170 thousand times atmospheric pressure. Sodium becomes a nonmetal at pressure of just under two million times atmospheric pressure, and at even higher pressures it is expected to become a metal again.

so even the stuff that lies on either edge of the periodic table (chemistry) isn't well defined!

Not even sure about the lustre of a fresh surface. Titanium always looks dull and diamond always sparkles. Crystalline iodine has a lustre, come to think of it.

[Bored chemist]

Titanium always looks dull

https://www.reddit.com/r/materials/comments/amvh0r/how_to_polish_titanium_to_a_mirror_finish/?rdt=53164

[neilep (OP)]

Indeed there are. Several elements have both metallic and non metallic allotropes, such as arsenic, antimony and selenium. Tin is normally considered a metal but it can also exist as a non metal. Hydrogen under enormous pressure has a metallic allotrope and I think phosphorus, a non metal can exhibit a metallic form but I am far from certain on that score.  PS: I just looked at the periodic table and it did not include selenium as a metalloid and instead listed tellurium. One I missed was silicon but also included is germanium which I would have thought to be a metal.

Fantastic. Thank ewe Paul. Fascinating stuff !

[neilep (OP)]

Linguistically, nothing says metal better than 'Iron'.  The called the first warship of the USA 'Old Ironsides' because the cannon balls just bounced off it, even though it was due to about 2/3 meter of oak and not iron at all.  'Steel' also has similar connotations.

As for elements with some of the strongest 'most metallic' properties, you want to go as far left in the periodic table as possible.  There is the naturally occurring Cesium, bested only by not-naturally occurring francium (ever heard of that?).  Not sure what those metallic properties are. Sure, alkaline (highly reactive), but there's other nice properties like strength (alloys are best), electrical conduction (gold, copper, soft stuff all).  Hard to pick one.

Thank ewe Halc....I appreciate this. Yes,  I have heard of Francium...it's not-naturally occurring ?  Human made ?

[neilep (OP)]

is there a borderline metal/non metal ?

In the periodic table shown here ( https://en.wikipedia.org/wiki/Periodic_table ), there is a dotted line showing the approximate border between metal and non-metal.

One of the characteristics of a metal is that it tends to give up an electron in a chemical reaction.
- In the elements down the bottom rows of the periodic table, the outer electrons are shielded by many shells of inner electrons, so they are more "willing" to give up an outer electron
- This is why the fuzzy borderline extends farther to the right in the lower rows of the periodic table.
- Conversely, in the top row/upper left, Hydrogen is close to the border. It is able to give up its sole electron in an acidic water solution. Under immense pressure (eg deep inside Jupiter), it is able to conduct electricity.

Thank ewe evan_au.  Most metals have high boiling points yes ?  apart from the alkaline metals ?

[paul cotter]

Mercury has a relatively low boiling point, a couple of hundred degrees c. Gallium which is liquid at body temperature and somewhat similar to mercury physically has a much higher boiling point.

[evan_au]

The smallest aromatic that I can think of is small, but certainly not zero dimensional.

Dimensions become relevant (or not) depending on the scale you are considering.

For example, gold nanoparticles used in stained-glass windows are 20-90 nanometers across (depending on the visible colour desired).
- Presumably, for light of a much longer wavelength (eg infra-red), they would be non-metallic (ie not refracting light, ie approximated as a 0-Dimensional metal particle)?
- Presumably, for light of a much shorter wavelength (eg ultra-violet), they would be metallic (reflecting light, ie approximated as a 3-Dimensional metal ball)
- These gold nanoparticles are much larger than cyclopropenium ions
https://www.nisenet.org/sites/default/files/catalog/uploads/8880/materialsgold_guide_31oct11.pdf