Transcript Section 3.1 – The Elements

Section 3.1 – The Elements
Period: 5
Group 7
Background
Introduction to the Elements
4 fundamental elements – fire, earth, water,
and air from Greece
Alchemists discovered elements & their
characteristics
Several “Fake” alchemists tried to change
metals to gold but failed and learned how
to prepare acids
Materials on earth & universe → ~ 100
different elements
Building blocks of all other substances
Example 1
Question: Why did the “fake” alchemists
can’t change metals into gold?
Solution: Because metal is not gold but
it is a category for all the elements
that are present in the state of metal.
“Father of Modern Chemistry”
Chemistry Explorers – Robert Boyle
(1627-1691)
Considered “Father of Modern
Chemistry”
Pioneering work on the properties of
gas
Science should be firmly grounded on
experiments
His experimental definition of an
element was accepted → proved air is
not an element → Greek system of four
elements died
Example 2
Question: How did Robert Boyle disapprove the
Greek system of four elements?
Solution: Because he used experiments to define
the meaning of element thus proved that air,
water, earth, and fire couldn’t be elements.
Abundances of Elements
115 elements with 88 natural
elements and 27 made-inlabs elements
Elements vary greatly in
abundance
9 elements account for most
of the compounds in earth’s
crust
Elements found in living
matter is very different from
the ones found in earth’s
crust
Abundances of Elements
Example 3
Question: What is the difference
between the elements in the earth’s
crust and in the human body?
Solution: The difference is the elements
found in the human body are crucial
for life while the ones found in earth’s
crust made up everything around us.
Names and Symbols for the
Elements
Names come from many sources
Reflects the place of discovery
Named in honor of famous scientists
or its properties
Abbreviations to simplify the written
word
Chemists use element symbols to
name the elements
Names and Symbols for the Elements
Example 4
Question: How are symbols for
elements given on the periodic table?
Solution: They are named after famous
scientists, places they were
discovered, or are based on t he
Greek language.
Trace Elements
Essential to human body
Helps the functioning of
thyroid gland or mains
proper calcium levels
Involved in metabolism
of sugars or production
of red blood cells
Affects our health and
behaviors
Trace Elements
Trace Elements
Example 5?
Question: How are elements such as
calcium, carbon, nitrogen, and iron
essential to our lives?
Solution: They help the human body to
function and keep us healthy and
strong.
Quiz
1. How do we make compounds or
molecules?
2. Why is air not an element?
3. How many forms of elements are
there and explain them?
4. What are element symbols for and
give an example?
5. How do elements affect our
environment and behaviors?
Answer Key
1.
2.
3.
4.
5.
By putting together different elements because they will
form ionic, covalent, or metallic bonds from sharing the
electrons.
Because air is a substance that can be broken down into
one or more simpler substances
There are 3 forms of elements: microscopic – single atom
of that element, macroscopic – sample of element large
enough to weigh on a balance, and generic – elements
are present in some form in the human body.
Element symbols are used to abbreviate or shorten the
elements’ names and an example would be phosphorus
with the symbol P.
Elements affect our environment and behaviors because
they appeared in our everyday surroundings and studies
have shown that elements in the hair do affect our
behaviors.
References
Charts and Pictures in Chemistry Textbook
http://rst.gsfc.nasa.gov/Sect20/ElementShells.JPG
http://upload.wikimedia.org/wikipedia/commons/a/aa/Periodic
_table.gif
http://www.particleadventure.org/images/page-elements/4elements.jpg
http://www.leeds.ac.uk/library/adopt-a-book/pics/boyle.jpg
http://serc.carleton.edu/images/NAGTWorkshops/health04/C
hyiPoster1Image.gif
http://www.scientificweb.com/en/Physics/Biographies/images/RobertBoyle2.jpg
http://www.ganeshaspeaks.com/blogImages/gold1%2001_24
022009.jpg