Introducing the Elements
From Chemistry Today 1
3rd ed
Discovering the Elements
 Earliest source of chemical energy was fire
 Approx 8000 years ago shiny materials appeared after heating
rocks in fires-> soft metals such as copper, silver, gold
 These three easily hammered into shapes for tools, weapons
jewelry
 Lead, tin, iron, mercury, carbon sulfur discovered around
the same time
Discovering the Elements
 About 5000 years ago, some tin was added to melted copper
and the new substance, bronze, was much tougher (for tools
weapons). Bronze Age began.
 Greek philosophers saw ordinary materials placed in
foundries in Alexandria, Egypt and large amounts of gold
and silver coming out. They thought the Egyptian craftsmen
were turning ordinary substances into gold! OMG !
 The search began for the “philosopher’s stone”
 The researchers were known as alchemists ( al from Arabic
meaning “the” and chymeia from Greek meaning “pouring” as
in molten metals
Discovering the Elements
 By middle of 18th century, phosphorus, zinc, arsenic,
antimony and bismuth were discovered
 After electricity was discovered, currents were passed
through compounds leading to discovery of sodium and
potassium (1807)
 In 1808, boron, magnesium, calcium, strontium, and barium
were also discovered.
 Now we have 90 naturally occurring elements of the 116
known
The periodic table
 Elements have been divided into metals, nonmetals and metalloids
 Metals ( from Greek metallon meaning “mine” are generally hard,
shiny, good conductors of heat and electricity, malleable & ductile,
and have high densities and boiling points e.g. gold, silver,
aluminum.
 Nonmetals are generally poor conductors of heat and electricity,
are not shiny or hard e.g. iodine, phosphorus, carbon (all solid),
oxygen, nitrogen, chlorine (gaseous).
 Metalloids have some properties of both metals and non metals
e.g. boron, silicon, germanium, arsenic, antimony, tellurium,
polonium.The staircase or solid zigzag line separates the metals
from nonmetals. Many of the elements bordering this line are
metalloids.
What’s your element score?
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Metal present in green pigments in plants used in
photosynthesis.
Most important metal in mortal, plaster, & Portland
cement.
Colourless, odourless gas used in hospitals to assist
breathing.
The element used in yellow coloured light from highway
lamps.
The element used in party balloons which some inhale to
sound like Mickey Mouse.
Latin Names for Elements
Chemical Symbol
Element Name
Latin Name
Na
Sodium
natrium
Cu
Copper
cuprum
Sn
Tin
stannum
Au
Gold
aurum
Pb
Lead
plumbum
K
Potassium
kalium
Ag
Silver
argentum
Sb
Antimony
stibium
Hg
Mercury
hydrargyrum
Fe
Iron
ferrum
The Periodic Table
 Around 1869 Dimitri Mendeleev , a Russian chemist, and
Lothar Meyer, a German chemist discovered that if the
known elements were listed in order of increasing atomic
mass, elements with similar chemical & physical properties
appeared at regular intervals in the list
 The modern periodic law states that when the elements are
arranged in order of increasing atomic number, elements
with similar properties occur at regular intervals. In other
words, the physical and chemical properties of the elements
are a periodic function of their atomic numbers
The Periodic Table
The Periodic Table
 Horizontal rows are periods (numbered 1-7) correspond to
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shells or energy levels for the electrons
Vertical columns are groups (numbered 1-18). Groups 1 & 2
have 1 and 2 valence (outer shell)electrons respectively.
Groups 13-18 have 3 to 8 valence electrons (i.e. Group # 10).
Note Group 18 has 8 valence electrons- a complete octet.
Groups 3 to 12 are the transition metals
Periods 6 & 7, have been compressed- i.e. the lanthanides (rare
earth elements) & actinides have been placed below and aligned
with groups 3 to 16