1. The table with a spot for everything
The Periodic Table
The table with a spot for everything

2. 1800’s- only 63 known elements
Many scientists look for patterns and similarities
that will allow them to organize the elements

3. developed the first useful table of the elements
Dmitri Mendeleev-
Russian chemist
developed the first useful table of the elements
arranged elements in order of increasing atomic
mass (average mass of all known isotopes)
when he arranged the elements this way, he made
several interesting observations:
1) The valence number (number of electrons in the outermost shell) of the elements occurred in a pattern of 1, 2, 3, 4, 3, 2, 1, etc.

4. 2) When the elements were arranged in rows
of 7, all of the elements in the resulting
columns had similar chemical and
physical properties
3) the properties of the elements in each row
was periodic in nature
Periodic- occurring in a regularly repeating pattern

5. As Mendeleev constructed his chart, every so
often he would have to leave a blank space in
order to make the known elements fit into
columns with similar properties:

6. elements that had not been discovered yet
he predicted that these empty spaces
represented
elements that had not been discovered yet
(he was right)
he also was able to accurately predict the properties
of these missing elements

7. Modern Periodic Table Despite the importance of his work, Mendeleev’s
table was not perfect…
when the elements were arranged according to their
atomic mass, several elements appeared to be
misplaced in terms of their properties (for example:
cobalt & nickel,
copper & zinc,
tellurium & iodine)
therefore, 50 years after Mendeleev came the…
Modern Periodic Table

8. Henry Moseley discovered the existence of neutrons
was the first to determine the atomic
number (number of protons) of elements
when Moseley arranged the elements
according to their atomic numbers
instead of their atomic masses, it
explained the “glitches” Mendeleev found

9. Moseley’s table is what is now known as the Modern Periodic Chart

10. Arrangement of the Periodic Chart

11. Rhodium Chemical Symbols a short-hand way of representing the elements
- symbols can either have 1 or 2 letters,
but never more than two!
- the first letter is always a capital letter
the second letter (if there is one) is always
lower case
Rhodium
Example-

12. symbol- R Rh h
ALWAYS lower case
ALWAYS capitalized

13. Ca Fe the letters used to make up an element’s
symbol can either come from
the elements name in English or
the element’s name in Latin
examples-
element-
calcium Ca
symbol-
(from its English name)
element-
iron Fe
symbol-
(from the Latin Ferrum)

14. 1.) columns of the table - called families
- there are 18 families of elements

15. elements within the same family have
similar but not identical properties
for example-
Family 1
(on the far left-hand side of the chart)
includes lithium, sodium, potassium,
rubidium, cesium, and francium
- all are soft, shiny, silvery-white metals
- all are highly reactive

16. But, of course, scientists don’t agree on what those groups should be…
there are several groups of elements
that may be made up of more than one
family of elements
But, of course, scientists don’t agree on what those groups should be…
- some of the more common groups include:
alkali metals
boron group
alkaline earth metals
carbon group
transition elements
nitrogen group
halogens
oxygen group
noble gases

17. 2.) Rows of the Table - called periods
elements in a period do not have
similar properties
as a matter of fact, the properties
change a great deal as you go across a
period
however…

18. there is a pattern
(that’s why they call it periodic):
as you go from left to right,
the first element is always going to be
a highly reactive solid.
the last element is going to be a
a non-reactive gas

19. - there are seven periods of elements
??????
??????
Hey, what up with those bottom two rows?

20. a section of periods 6 and 7 have been
cut out and put below to make the
chart easier to read
cut

21. the rare earth elements
- elements 57 – 71 are called the lanthanide series
(because they come right after the element lanthanum)
- elements 89 – 103 are called the actinide series
(because they come right after the element actinium)
- together, these two rows of elements are called
the rare earth elements

22. using the periodic table
- each element is found in a separate square
- each element contains at least four facts:
1.) the element’s name
2.) the element’s symbol
3.) the element’s atomic number
4.) the element’s atomic mass

23. Types of Elements
elements can be grouped into three
main categories:
1.) metals
2.) nonmetals
3.) metalloids

24. Metals
of the known elements, over 90 are
metals

25. all but three
(mercury,
gallium,
and cesium)
are solids at room temperature

26. - good conductors of electricity and heat
- usually have high melting points
- usually shiny
- are ductile
(can be pulled into thin wires)
- are malleable
(can be hammered into thin sheets)

27. Nonmetals
- of the known elements, 16 are nonmetals

28. at room temperature, 10 are gases, 5 are
solids, and 1 (bromine) is a liquid
are poor conductors of electricity and
heat
- have very low melting points
- solids and liquids have dull surfaces
- solids are brittle
(break apart easily)

29. Metalloids found along the dividing line between
the metals and nonmetals

30. - all are solids at room temperature
have properties of both metals and
nonmetals
includes: boron, silicon, germanium,
arsenic, antimony, tellurium,
polonium, and astatine

31. Periodic Properties
of the
Elements

32. you know that some properties of elements vary in a regular way as you go from left to right across a period, but which ones?
- there are 4:
1.) electron arrangement
2.) reactivity
3.) atomic size
4.) metallic properties

33. 1. electron arrangement
the valence number of an element
refers to the number of electrons in
the outermost shell

34. - only the valence electrons are involved in bonding
- valence electrons can be gained, lost, or shared
- elements on the left side tend to lose electrons easier
- elements on the right tend to gain electrons easier

35. for example:
Lithium
Oxygen
found on left
side of chart
found on right
side of chart
- has 1 valence
electron
- has 6 valence
electrons
- tends to lose
electrons easily
- tends to gain
electrons easily

36. 2. reactivity - the ability of an element to bond with other elements
- elements on the left side tend to
react a lot with other elements
- elements on the right side do not
react at all

37. 3. atomic size - within a period, atoms get smaller as
you go from left to right
why?
because as you add electrons to a shell, there is more magnetic attraction between the electrons and the protons

38. 4. metallic properties (oh, you remember…
good conductor, high melting point, shiny, ductile, malleable, etc…)
- as you go from left to right, the
elements become less metallic in
nature