valuable metal, platinum is harder than silver, but
also flexible and malleable. While platinum is definitely
susceptible to cold working, most of the times it
is processed at temperatures ranging from 800 to 1,000
degrees Celsius. When a small amount of iridium is
added, platinum noticeably gains in hardness, but
loses some of its malleability. Because it expands
at almost the same rate as glass, it is also used
to connect various glass tools. It stays in a very
stable state within the air or water, not changing
its state even when heated. It is also durable against
acidic and alkaline effects. However, it melts slowly
in aqua regia and corrodes when heated along with
caustic alkali. It also reacts in heat to such other
elements as fluoride, chloride, sulfur, and selenium.
It absorbs carbon at a high temperature and discharges
it back when cooled. This is when the surface of platinum
becomes malleable. Therefore, it is advised that you
avoid heating platinum up with coals, corks, or carbon-rich
reducible flames. It can be mixed with arsenic, antimony,
bismuth, tin, lead, and so forth to create alloys
whose melting points are much lower than that of pure
platinum. Platinum, in the form of fine powder, can
absorb an amount of hydrogen that is over 100 times
as large as its own volume. Heat-applied platinum
lets hydrogen permeate itself. Platinum also absorbs
oxygen and helium: absorbed hydrogen and oxygen is
then activated. This makes platinum an important catalyst
in the process of oxidation and reduction.
metal, pure titanium is malleable and flexible, but
gains in hardness upon heating. Given its resistance
to corrosion, titanium is one of the most important
elements in various industries. It can be found in
two different crystalline types: alpha (¥á) and beta
(¥â). The hexagonal alpha type maintains a stable state
in room temperature. When heated beyond 882 degrees
Celsius, it turns into the cubic beta system. With
the hardness of 4.0, it is extremely vulnerable in
cold and can be even turned into powder. When heated,
it can be elongated in linear shapes. It is almost
as strong as carbon steel, twice as strong as steel
and six times as strong as aluminium. It has little
heat-conductivity or heat-expandability and changes
little in terms of strength under 400 degrees Celsius.
While stable in the air, it turns into titania when
heated up in oxygen. Titanium also reacts to hallogens
in heat. It is less corrosive than steel in acid.
It is only second to platinum in terms of corrosion-resistance
in seawater. Titanium is also used along with various
other materials to create alloys.
metal, this unmealleable, brittle material is limited
in terms of processability and cannot be processed
at all when it contains even a minuscule amount of
other substances. Strong against acidic or alkaline
effects and even the aqua regia, iridum still melts
in strong chloric acid when heated in the presence
of sodium perchlorate. When heated in the air, iridium
begins to oxidize at 800 degrees Celsius or higher.
Because its oxidants dissolve at high temperatures,
it no longer oxidizes at 1140 degrees Celsius or beyond.
It reacts to sulfur and phosphorus in heat, and even
more easily, relatively speaking, to chloride. Iridium
compounds are found in the valences of 1, 2, 3, 4,
and 6, 3 being the most common.