Relation of discovery of metals to reactivity

By: Salah Mahmoud 8A Relation of discovery of metals to reactivity

Introduction Through 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 Tantalum 1803 Iridium, Palladium, Rhodium 1807 Potassium, Sodium 1808 Boron, Barium, Calcium, Magnesium, Strontium 1814 Cerium 1817 Lithium, Cadmium, Selenium 1823 Silicon 1827 Aluminum 1828 Thorium 1830 Vanadium 1839 Lanthanum 1843 Erbium, Terbium 1844 Ruthenium 1860 Cesium, Rubidium 1861 Thallium 1863 Indium 1875 Gallium 1878-1885 Holmium, Thulium, Scandium, Samarium, Gadalinium,Praseodynium, Neodynium, Dysprosium 1886 Germanium 1898 Polonium, Radium 1899 Actinium

Metals discovered in the 20th century • 1901 Europium • 1907 Lutetium 1917 Protactinium 1923 Hafnium 1924 Rhenium 1937 Technetium 1939 Francium 1945 Promethium 1940-61Transuranium elements. Neptunium Plutonium Curium Americum Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium

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

Relation of discovery of metals to reactivity