45. A(n) ELEMENT is a pure substance that can not be broken down into any other substance by some
physical or chemical method and from which all more complex forms of matter or substances are made when
they are combined together in different ways and in different amounts. P. 9, 70, VCR: Atoms and Molecules
46. The smallest particle of any element that you can have which still possesses all of the physical and
chemical properties of that element is a single ATOM of that element. P. 10, VCR: Atoms and Molecules
47. Nearly 2000 years ago the Greek philosopher DEMOCRITUS gave us the word atom
when he said that all matter was composed of tiny indivisible particles called “atomos.” P. 73, VCR: Atoms
and Molecules
48. At the present time about 118 different elements have been discovered and officially
recognized and named. P. 84 - 85, VCR: Atoms and Molecules, VCR: Changes in Properties of Matter
49. An orderly arrangement of the 118 different elements on a chart according to each element’s unique
chemical symbol, atomic number, atomic mass number, and physical and chemical properties is called
the PERIODIC TABLE of elements. P. 82, VCR: Atoms and Molecules
50. The periodic table of elements was originally created by a Russian chemist named DMITRI
MENDELEEV and later it was modified and changed to the modern version of the periodic table that we use
today by a British chemist named HENRY MOSLEY P. 81
51. Each element found on the periodic table of elements has a unique single letter (Hydrogen – H), two
letter (Helium – He ) or three letter (Unnilquadiam – Unq) abbreviation which is called the
CHEMICAL SYMBOL of that element. P. 83
52. JONS BERZELIUS created the unique one, two or three letter chemical symbol for each element.
53. In addition to each element having a unique chemical symbol each element found on the periodic table of
elements also has a unique ATOMIC number and ATOMIC MASS number P. 83, VCR: Atoms and
Molecules
54. The atomic number of an element is usually always SMALLER in numerical
value than the atomic mass number of that element. P. 83, VCR: Atoms and Molecules
55. The atomic number of the element
10.811
B
5
is 5 . P. 83, VCR: Atoms and Molecules
56. On the periodic table of elements those elements which have an atomic number of 1 (Hydrogen) to
92 (Uranium) are naturally occuring elements which can be found to exist somewhere in the
earth’s land, water, or air.
57. On the periodic table of elements those elements which have an atomic number of 93 (Neptunium)
to 118 (Ununoctium) are synthetic or man made elements which have a very short life span that
only allows them to be made in a laboratory under very special conditions.