the periodic table chapter 5. alchemy & diderot's alchemical chart of affinities (1778):
TRANSCRIPT
The Periodic Table
Chapter 5
Alchemy & Diderot's Alchemical Chart of Affinities (1778):
Dalton's elements and symbols (1808):
The Bayley Pyramid Periodic Table
Mohammed Abubakr's circular periodic table is one alternative to the standard periodic table of the elements.
A Spiral Periodic Table by Prof. Thoedor Benfey
Spiral Periodic Table
The Dufour Periodictree
AtomFlowers A periodic table that gives a representation of the electron orbitals that look like flowers
Chinese periodic table
Chapter 5 section 1pg 126-129
Organizing the Elements
• 1750 = 17 elements known– Mostly common metals
• After 1750, more chemists begin to study elements many more elements discovered faster
• Needed a way to organize elements– 1789 Antoine Lavoisier grouped
elements based on type• Metals, nonmetals, gases & earths
– 1860 Mendeleev
• What was going on in history during this time?
• Why is this organization limited?
Mendeleev’s Periodic Table• Organized elements like
a deck of cards– 1st order by mass– 2nd property patterns
• esp. rxns with O & H
• Draw an example of ordering strategy
A 2 4 5 6
8
7
9 10 QJ K
A 2 43
5 6 87
9 10 QJ
K
Mendeleev’s Periodic Table• Organized elements like
a deck of cards– 1st order by mass– 2nd property patterns
• esp. rxns with O & H
– Rows (called periods)• Mass increases from left to
right
– Columns (called groups)• Mass increases from top to
bottom• Similar properties
• Draw an example of ordering strategy
• Draw a small periodic table to illustrate rows and columns
groups
periods
groupspe
riods
Mendeleev’s Periodic Table
• Left blanks for elements not discovered yet
• Why remember Mendeleev if he wasn’t the first to come up with a P.T.?– Best organization strategy– Used to make accurate predictions about
what elements were yet to be discovered
Mendeleev’s Periodic Table• EX: Gallium
– Predicted similar properties to aluminum» Soft metal» Low melting point» Density ~ 5.9 g/cm3
– Truth about gallium:» Soft metal» Melting pt 29.7˚C» Density 5.91 g/cm3
• Further proof his PT was good:– Discovery of scandium and germanium
Would gallium be a solid, liquid or gas at room temperature (20-22˚C)?
Check your understanding
• Pg 126 reading strategy
• Pg 127 figure 3
• Pg 129 figure 4 (already done )
• Pg 129 assessment, #1-8
REMINDER!!!
• Open note reading quiz
WARNING
Chapter 5 section 2pg 130-138
5.2
• More on Mendeleev (note: 1860)– Did not know about protons– Did not know that all atoms in an
element have the same # of protons– His PT arranged by mass, ours by atomic
#
5.2
• Periods– Rows (side-to-side)– # of periods = # of electron energy
levels
• Groups – Columns (up-and-down)– Similar properties– Similar electron configuration
• Determines chemical properties
5.2
• Atomic mass– # given on PT is an average of the element’s
isotope masses
• Weighted avg.s– Atomic mass = avg. mass of isotopes
compared to how common they are
• AMU– Atomic Mass Unit– Unit of mass for atoms (like grams but much
smaller!)
5.2
• Classes of Elements– Solid, liquid, gas dependant on temp.
– Occur naturally vs. those that do not (man-
made)
– Metals, nonmetals, metalloids
5.2
• Metals– Most elements are metals (+75%!)– Physical properties
• Good conductors• Solids at room temp. (except for Hg)• Malleable• ductile
– Chemical properties• Some are reactive, others are not
(to rust or not to rust?)
5.2
• Special Metals– Transition metals
•Chemical properties–Form compounds with distinctive
colors•Lanthanide & actinide series
5.2
• Nonmetals– Physical properties
• Poor conductors• Brittle • Most are gasses at room temp. (low bp)
– Chemical properties• Vary some very reactive, others not at all• Most reactive = group 17• Least reactive = group 18
5.2
• Metalloids– Physical properties
• Conductivity varies with temp.
• Semi-conductors computer chips “Silicon Valley”
Chapter 5 section 3pg 139-149
Part I: pg 139 & ionsPart II: pg 140-145Part III: pg 146-149
5.3 Part I
• Valence electrons– Electrons in the outermost energy level– Chemical properties depend on the
number of valence electrons– What does this mean after learning
about the organization of the PT?
Groups have similar properties so they must also have similar #s of valence electrons
5.3 Part I
• Octet– magic # in chemistry =
– Valence orbitals can hold no more than 8 e-
– All atoms want a full valence (8 e-) or none (all or nothing)
– Exceptions: H & HeWhy?
5.3 Part I• Ions
– Atoms that gain or loose e- to fill or empty the valence orbital
1p+ +1
5.3 Part I• Ions
– Atoms that gain or loose e- to fill or empty the valence orbital
2p+ Ø
5.3 Part I• Ions
– Atoms that gain or loose e- to fill or empty the valence orbital
3p+ +1
5.3 Part I• Ions
– Atoms that gain or loose e- to fill or empty the valence orbital
4p+ +2
5.3 Part I• Ions
– Atoms that gain or loose e- to fill or empty the valence orbital
5p+ +3
5.3 Part I• Ions
– Atoms that gain or loose e- to fill or empty the valence orbital
6p+ +4
`
5.3 Part I• Ions
– Atoms that gain or loose e- to fill or empty the valence orbital
6p+ -4
`
5.3 Part I• Ions
– Atoms that gain or loose e- to fill or empty the valence orbital
7p+ -3
`
5.3 Part I• Ions
– Atoms that gain or loose e- to fill or empty the valence orbital
8p+ -2
`
5.3 Part I• Ions
– Atoms that gain or loose e- to fill or empty the valence orbital
9p+ -1
`
5.3 Part I• Ions
– Atoms that gain or loose e- to fill or empty the valence orbital
10p+ Ø
`
5.3 Part I• Ions
– Atoms that gain or loose e- to fill or empty the valence orbital
11p+ +1
`
5.3 Part II
• Groups– Alkali Metals– Alkaline Earth
Metals– Transition Metals– Boron Family– Carbon Family– Nitrogen Family– Oxygen Family– Halogens– Noble Gases
• Group #– 1– 2– 3-12– 13– 14– 15– 16– 17– 18
5.3 Part II
• For each group:– List the elements in that group– How many valence electrons do they
have?– What kind of ions do they form?– Are they reactive?– What are some of their physical and
chemical properties?– Where are they found?– What are they used for?
5.3 Part III
• Elemental Friends & Foes
– Add to your group list
Transition Metals
Groups 3-12
Transition Metals
• 1st elements discovered• Make colorful compounds
– Often used to tint/color glass
• Metals– Good conductors– Malleable– Ductile– Solids at room temp. (exception Hg)
Transition Metals
• All ions are positively charged
• Valence electron #s vary Type of ion
formed varies
• Example: Iron – Fe2+ and Fe3+
Transition Metals
• Most mined
• Many uses:– Wires– Construction– Decoration