• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

The nineteenth century was the golden age for the discovery of elements.

Extracts from this document...


"The nineteenth century was the golden age for the discovery of elements. Scientists began to look for patterns of behaviour between elements."*1 Johann D�bereiner, a German chemist, was the first to attempt to categorise the elements. He used their atomic weights, which we now know as atomic masses. In 1863, John Newlands, produced something that he called the 'Law of Octaves'. He used this to produce his own version of the periodic table, but Newlands came across some problems. "After about 20 elements his table became ragged,"*2 Newlands had left no gaps for undiscovered elements and even had to put two elements in one space. It was Dimitri Mendeleev, a Russian chemistry professor, in 1869 that produced a much improved table. He amended many of the atomic weight values and left gaps for undiscovered elements. "Mendeleev was so confident of the basis upon which he had drawn up his table that he made predictions about elements which had yet to be discovered."*3 Since Mendeleev's table all the gaps he left have been filled, three of the five elements whose properties he predicted were found within fifteen years, and a whole new group has been introduced - the Noble Gases. ...read more.


Gallium has some very unusual properties, some which suggest that it is a metal and some that imply it is a non-metal. Its physical properties, a melting point of 29.78�C (which is almost UK room temperature) making it a liquid metal along with Mercury and Caesium. It also has an extremely high boiling point, 2403�C; together with its low boiling point gallium has the 'widest liquid range' of any element discovered so far. Gallium is also denser as a liquid than as a solid, as is water. Gallium's chemical properties include, dissolving in acid and alkalis, evolving hydrogen. Aluminium and gallium both have the same reaction when mixed with hydrogen ions. *8Reaction between aluminium and hydrogen ions 2Al(s) + 6H (aq) 2Al (aq) + 3H (g) Reaction between gallium and hydrogen ions 2Ga(s) + 6H(aq) 2Ga (aq) + 3H (g) The same happens in the reaction with gallium and hydroxide ions; Gallium and hydroxide ions 2Ga(s) + 2OH (aq) + H2O(l) 2[Ga(OH) ] (aq) + 3H (g) ...read more.


This resulted in the creation of element 107 - bohrium. Cr + Bi element *13 The GSI formed four more elements over the following years; the most recent was February 1996, they fired zinc ions at a lead metal target, creating element 112 - ununbium. Zn + Pb element *14 In the nineteenth century atomic spectroscopy was used commonly by scientists to discover new elements over 140 years of Mendeleev's periodic table three of his predicted elements were discovered, eka-aluminium, eka-boron and eka-silicon. 1875 - Paul Emile Lecoq de Boisbaudran discovered germanium, (eka-aluminium), 1881 - Lars Nilson found scandium, (eka-boron), 1886 Clemens Winkler found germanium, (eka-silicon). Since then the UNILAC accelerator was introduced. "There are 92 naturally occurring chemical elements"*15 from hydrogen to uranium. Scientists have gone beyond uranium by purposely synthesising 'artificial' elements; this is achieved using the UNILAC accelerator. This involves firing beams of metal ions into a rotating metal target with greater force, the nuclei of the atoms fuse together creating a new element. In 1940, Ed McMillan created the first artificial element - Neptunium. Over the 25 years Glenn Seabory, of the University of California at Berkeley discovered an entire family of new elements, 94 to 102. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our GCSE Classifying Materials section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related GCSE Classifying Materials essays

  1. Marked by a teacher

    Chemistry revision notes. Atomic Structure and Bonding, Electrolysis, Acids and Alkalis.

    5 star(s)

    Copper is deposited at the negative cathode 3. The solution remains the same as it is losing copper ions at the cathode but gaining them at the anode. This is used industrially to purify copper. A lump of impure copper is used as the anode and a rod of pure copper as the cathode.

  2. Marked by a teacher

    Chemistry Revision Notes on atomic structure, nuclear power and the periodic table

    4 star(s)

    Water or graphite could be used. > During the chain reaction, dangerous radioactivity is produced where in order to contain this, the reactor assembly is shielded by thick walls of steel and/or concrete. This radioactivity can be: * Gamma rays - these are short-wave electromagnetic radiation and can be stopped by 1cm of lead or 1m of concrete.

  1. The Period 3 Elements

    Weak forces between molecules Weak forces between molecules Weak forces between molecules Giant structures and boiling points The chlorides with giant structures (NaCl and MgCl2) * Have high boiling points; * Require a large amount of energy to break the strong forces between their particles; * NaCl and MgCl2 have

  2. Free essay

    Periodic table

    atoms come into contact and lose or gain electrons and form a compound they are known as ionic compounds. Ionic compounds form when metal and non-metal atoms combine. Electron Dot Diagrams - they only show the symbol of the atom and use dots for the Outer shell of atoms.

  1. Development of the Periodic Table ...

    the undiscovered elements would be found and they would fit in perfectly. Fortunately for Mendeleev, Paul Lecoq de Booisbaudran discovered an unknown substance when he was examining zinc sulfide ore, using spectroscopy. When looking at its spectrum, he noticed a faint violet line that wasn't usually present in the known spectrum of zinc sulfide.

  2. The discovery of the elements.

    Mendeleev called gallium eka-aluminium (see table on next page) before it was discovered, as it was one element below aluminium in his periodic table. He even predicted its chemical and physical properties. This then gave a big boost to Mendeleev's idea of the periodic table. eka-aluminium (Ea) Gallium (Ga)

  1. Throughout the nineteenth century many scientists attempted to classify the chemical elements according to ...

    Cobalt & Nickel and Platinum & Iridium. In 1869 Russian chemistry professor Dimitri Mendeleev published his table of periodic law - The properties of the elements are a periodic function of their atomic weights5. Mendeleev's approach to classifying the elements differed from that of his predecessors in that he

  2. To conjecture the structure and bonding of eight unknown solids by analysis of experimentally ...

    melting point of each solid, replacing each boiling tube after their contents have melted until melting points for all four test-tubes have been obtained * Make notes on any additional observations 1Paraffin oil heats more slowly and consistently allowing for a more gradual and measurable increase in temperature 2Only four

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work