RELATION OF DISCOVERY OF

METALS TO REACTIVITY

By: Salah Mahmoud 8A

IntroductionThrough out the years many people have been trying to discover new elements, metals are one of the most important. I believe that the year of discovery relates to its reactiveness with other chemicals, I believe this because the more reactive a metal is the harder it is to be discovered because it would have reacted with something else, whether it is water, air or even acid, so by the time a reactive metal is found it would look or act differently, if it is unreactive it would just sit there waiting to be discovered. This project relates to the Area of Interaction Human Ingenuity because it science is all about systematic study of all of what is around us from materials and elements, which shows us that the meaning of discovering all of these metals, and the way that they had to discover them. For all this discovery of humans definitely had an impact on us and the way we live.

Reactivity Series

Gold Gold is virtually placed at the bottom of the reactivity series, being

the first metal discovered at 6000 BC, gold was easily recognizable because of its shining yellow color, it is considered uncombined in nature which is why it was found in such an early stage, it did not react with other chemicals, it also does not get oxidized which is why it was attracted by humans especially at the ancient Egyptian and Greek times.

The electrons per shell for gold is 2, 8, 18, 32, 18, 1 adding to an atomic number of 79 electrons.

Uses of gold include monetary exchange, investment, jewelry, medicine, food and drink, industry, electronics and commercial chemistry.

Gold is simply extracted by mining, but nowadays with new technology it is becoming easier except for the fact that the gold is becoming dust.

Copper Copper was also discovered early, in the 4200 BC,

uses of copper include tools, weapons and home utensils.

The electrons in copper are 2, 8, 18, 1 with the atomic number if 29.

Copper is extracted by mining, but when exposed to water/ oxygen it can oxidize.

Copper is in the bottom of the reactivity series, not last but still in rate of showing that it was found much earlier than most metals, meaning it has low reactivity.

Potassium Potassium was discovered in 1807, some uses of potassium

would include of being used in fertilizer, used to stop the heart for heart surgery, some is added to flour to make it stronger.

The number of electrons are 2,8,8,1 adding up to an atomic number of 19.

Potassium can be isolated by electrolysis of its hydroxide in an ongoing changing process.

Potassium is on the top of the reactivity list being one of the most reactive metals, if not the most, this makes sense because potassium was only found about 2 centuries ago while others were discovered many millenniums ago.

Before the 1800’s there were only 12 known metals Gold Silver Copper Lead Mercury Iron Tin Platinum Antimony Bismuth Zinc Arsenic

7 of these metals called “The metals of Antiquity” were founded during the time of ancient civilizations.

Gold (ca) 6000BC Copper,(ca) 4200BC Silver,(ca) 4000BC Lead, (ca) 3500BC Tin, (ca) 1750BC Iron (ca) 1500BC Mercury, (ca) 750BC

What you might realize is that most of these metals are on the top of the reactivity series, if not they are at least around the middle like iron,

Platinum, one of the least reactive metals is excluded from this, but it is only one metal not really effecting our hypothesis, for it was found in the 16th century.

Metals discovered in the 18th century

(1735) Cobalt (1751) Nickel (1774) Manganese (1781) Molybdenum (1782) Tellurium (1783) Tungsten (1789) Uranium (1789) Zirconium (1791) Titanium (1794) Yttrium (1797) Berylium (1797) Chromium

Metals discovered in the 19th century 1801 Niobium 1802 Tantalum1803 Iridium, Palladium, Rhodium1807 Potassium, Sodium1808 Boron, Barium,

Calcium, Magnesium, Strontium1814 Cerium1817 Lithium, Cadmium, Selenium1823 Silicon1827 Aluminum1828 Thorium1830 Vanadium1839 Lanthanum1843 Erbium, Terbium1844 Ruthenium1860 Cesium, Rubidium1861 Thallium1863 Indium1875 Gallium1878-1885 Holmium, Thulium, Scandium, Samarium, Gadalinium,Praseodynium, Neodynium, Dysprosium1886 Germanium1898 Polonium, Radium1899 Actinium

Metals discovered in the 20th century

1901 Europium 1907 Lutetium1917 Protactinium1923

Hafnium1924 Rhenium1937 Technetium1939 Francium1945 Promethium1940-61Transuranium elements.NeptuniumPlutoniumCuriumAmericumBerkeliumCaliforniumEinsteiniumFermiumMendeleviumNobeliumLawrencium

Observation From all this information I can see that

the most reactive metals were the ones that were found later on in time, unlike the ones that were discovered early were least reactive as showed to us by the reactivity series.

Conclusion When looking at the early stage of humanity we can tell that the metals that

were reactive put the scientists in a bigger challenge every time. This is because most metals that were reactive were more than expected to be in a different state then it really is, mixed with other elements to create a compound, so it needed more endeavoring work than a regular metal like gold or platinum, because they were not affected. But over the years metallurgists have become more advanced and innovated, so their potential to locate and separate metals from their compound state became easier. But it doesn’t mean that their work was done, it still took a lot of work to uncover, not only did it have to be found but it had to undergo many steps too, like separating it from its gangue or its new compound state, concentrate it and many more. If you gaze off from a few of the discoveries then the reactivity series looks perfect with the fact that the most reactive are on the top, which also means that they were discovered the latest, a few examples of unwanted information would be like platinum which was discovered late, and iron which was discovered too early. But overall we can still use the reactivity series as a way to check the discovery date, which means that my hypothesis, was correct.

Bibliography http://www.slideshare.net/Isha1597/relation-between-reactivity-of-a-metal-and-the-date-it-was-

discovered http://en.wikipedia.org/wiki/Gold http://wanttoknowit.com/uses-of-potassium/ http://en.wikipedia.org/wiki/Copper http://en.wikipedia.org/wiki/Potassium http://neon.mems.cmu.edu/cramb/Processing/history.html