In 1869 Dmitri
Mendeleev published the first periodic table then having only having discovered
66 chemical elements at the time. Since then we have discovered 60 new chemical
elements which have been on this earth the whole time but have not been discovered
without modern science. So what is a
chemical element? Let’s start with h2o in other words water, one drop of water
contains and unimaginable number of molecules. Alright now we are going to talk
a little bit about Atoms Molecules and compounds. Every substance has physical
properties that we can measure and describe. Substances also have chemical properties,
and chemical properties that can be seen with the naked eye is called
macroscopic.
The underlying substance which
is called microscopic can be explored behind a magnifying glass or microscope. Further magnification eventually reveals the
building block of matter. This is what we like to call the molecular or atomic view.
The fundamental unit of a chemical
substance is called an atom. The word atom is derived from the Greek word
atommos meaning “uncuttable”. The atom of a molecule is the smallest possible
particle of a substance. Atoms combine to make all substances in the world
around us, but they do so in very orderly ways. Atoms are composed of three
primary fundamental particles: called electrons, protons and neutrons. Each
element has a unique combination of protons and electrons in an atom of one
element is different from that in a atom of any other element? The answer is
yes, if you could compare the number of electrons and protons in your unknown
atom with a list of the electrons and protons in atoms of each known element.
Most substances that we see in our day to day life are made up of small units
called molecules. The simplest molecules contain just two atoms. For example, a
molecule of hydrogen is made up of two hydrogen atoms. Each element is represented by a unique one
or two letter symbol. For example the symbol for Hydrogen is an H, Oxygen’s
symbol is an O, and nitrogen’s symbol is an N.
A chemical compound is a substance that contains more than one element.
The relative amounts of the elements in a particular compound do not change:
Every molecular substance
contains a characteristic number of atoms of it’s constitute element. For
example, every water molecule contains two hydrogen atoms and one oxygen atom. To
describe this atomic compound chemist write the chemical formula for water H2O.
A little over 98 ½ % of the earth
is made up of eight of these elements: Iron (Fe)
Oxygen (O) Silicon (Si)
Magnesium (Mg) Nickel (Ni) Sulfur (S) Calcium (Ca) and Aluminum (Al). Oxygen
and Iron by themselves make up about 65% of the earth. But then if we look at
the universe about 97% of it is two elements, the two on the top right side of
the periodic table, hydrogen (H) and helium (He).
Most of the elements were not
easy to find. They were very difficult to find. They had to be discovered, and
they certainly were not found conveniently labeled and staked in such neat rows
as we find them on the periodic table of elements In
Benjamin Wiker’s book the mystery of the periodic table he says: “Indeed when
we look at the nice neat, and strait rows of elements we might think that it
was a nice, neat and strait road to their discovery. Nothing could be further
from truth. It was a long difficult journey much like the perilous wanderings
of Odysseus on Homer’s great epic tale the Odyssey.”
Those of us who were familiar with the state of inorganic chemistry in universities twenty to thirty years ago will recall that at that time it was widely regarded as a dull and uninteresting part of the undergraduate course. Usually, it was taught almost entirely in the early years of the course and then chiefly as a collection of largely unconnected facts. On the whole, students concluded that, apart from some relationships dependent upon the Periodic table, there was no system in inorganic chemistry comparable with that to be found in organic chemistry, and none of the rigor and logic which characterized physical chemistry. It was widely believed that the opportunities for research in inorganic chemistry were few, and that in any case the problems were dull and uninspiring; as a result, relatively few people specialized in the subject... So long as inorganic chemistry is regarded as, in years gone by, as consisting simply of the preparations and analysis of elements and compounds, its lack of appeal is only to be expected. The stage is now past and for the purpose of our discussion we shall define inorganic chemistry today as the integrated study of the formation, composition, structure and reactions of the chemical elements and compounds, excepting most of those of carbon. Ronald Sydney Nyholm
Those of us who were familiar with the state of inorganic chemistry in universities twenty to thirty years ago will recall that at that time it was widely regarded as a dull and uninteresting part of the undergraduate course. Usually, it was taught almost entirely in the early years of the course and then chiefly as a collection of largely unconnected facts. On the whole, students concluded that, apart from some relationships dependent upon the Periodic table, there was no system in inorganic chemistry comparable with that to be found in organic chemistry, and none of the rigor and logic which characterized physical chemistry. It was widely believed that the opportunities for research in inorganic chemistry were few, and that in any case the problems were dull and uninspiring; as a result, relatively few people specialized in the subject... So long as inorganic chemistry is regarded as, in years gone by, as consisting simply of the preparations and analysis of elements and compounds, its lack of appeal is only to be expected. The stage is now past and for the purpose of our discussion we shall define inorganic chemistry today as the integrated study of the formation, composition, structure and reactions of the chemical elements and compounds, excepting most of those of carbon. Ronald Sydney Nyholm
