Transcript Metals and Reactivity

Does a connection or relationship
exist between the
reactivity of a metal and when it was
discovered?
Aim.
• I will try to prove if there is indeed any
relationship between the reactivity of a metal
and when it was discovered.
• I will do this using metals from the reactivity
series like Gold, Platinum and Copper
The ReactivitySeries.
Metal’s Discovery Date.
Potassium.
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Symbol: K (Kalium)
Atomic Number: 19
Atomic Mass: 39.0983.
Potassium is a highly reactive alkali metal that
was discovered in 1807 by Sir Humphrey Davy
. It reacts with oxygen rapidly to form oxides
of itself e.g. potassium oxide and with water
to form hydroxides (KOH) and Hydrogen.
Calcium.
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Symbol: Ca
Atomic Number: 20
Atomic Mass: 40.078
Calcium is an alkali earth metal reacts with air
to form Calcium Oxide (CaO). If this is added
to water, Ca(OH)2 is formed otherwise known
as slaked lime. Calcium was discovered in
1808 by Sir Humphrey Davy.
Magnesium.
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Symbol: Mg
Atomic Number: 12
Atomic Mass: 24.305
Magnesium is an alkali earth metal and
constitutes about 2% of the earths crust mass.
This makes it the eighth most abundant metal
in the world. It was discovered in 1808, by
suprise!! Sir Humphrey Davy.
Iron.
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Symbol: Fe (Ferrum)
Atomic Number: 26
Atomic Mass: 55.847
It is t fourth most abundant element in the
earth’s crust. Iron was discovered around
2000BC. It is the first element in the
transitional series in the periodic table. Reacts
with air and water to form Ferrous Oxide
(Fe2O3)otherwise known as Rust.
Gold.
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Symbol: Aurum (Au)
Atomic Number: 79
Atomic Mass: 196.96655
Gold is a transition metal. It is very unreactive, even if left in oxygen or water for
long periods of time. Gold was discovered
around 5000BC. Because of its low reactivity,
it is found freely and doesn’t have to be
mined.
Pattern?
• Do you see a pattern now?...no?... Okay let me
explain.
• All the un-reactive or rather less reactive metals
were found years before the more reactive ones.
Why? You ask: well because back then, the
technology needed to isolate and mine these
various metals were not available so its therefore
plausible that only natural occurring metals like
Gold, Iron, Silver e.t.c. were used because no
extra refining was necessary.
Conclusion.
• So Yes there is a noticeable relationship
between the discovery date of a metal and the
reactivity of the metal. The only lesser
reactive metal which wasn’t found very long
ago (16th century) is Platinum, but this is
because it is extremely rare and only occupies
about 0.001%!!! And so it is extremely
expensive