Accelerated ChemistryChapter 5 NotesMr. Seidel
(Student edition)
Chapter 5 problem set:4, 6, 17, 18, 22, 23, 24, 27, 29, 35, 36, 38, 41, 45
Useful diagrams: Every single diagram/photograph/drawing has something that you can learn from in this chapter. You should be familiar with any and all figures if you wish to understand this chapter as fully as possible.
5.1Origin of the periodic table
Dimitri Mendeleev - publish first real periodic table - 1869
based on ______
listed elements in order of ______
left spaces for ______
Eka - AluminumGa (1875)
atomic mass6869.7
density5.95.9
melting pointlow29.8 Co
oxide formulaE2O3Ga2O3
also predicted Eka - ______
Mendeleev formulated the original Periodic Law - Properties of elements are a periodic function of their .
1911 - Mosely (English) discovers the so....
new Periodic Law - Properties of elements are a periodic function of ______.
*** History lesson - After his brilliant discovery, Mosely was drafted into the infantry to fight for the crown in WW I. He was killed. Only after the war was it realized that scientists should probably not be drafted into combat roles. That policy exists to this day.
5.2Electron configurations and the periodic table
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Names of Families
Group 1 - Alkali Metals - These compounds are not found alone in nature - why? explosive with water - they are stored under kerosene - very reactive. They react with nonmetals to form salts. They are silvery, shiny (luster), have a low melting point, and are soft (so soft, you can cut them with a knife). They are malleable (able to flattened into a sheet) and ductile (able to be drawn into a wire). Sodium and Potassium are particularly important in body chemistry.
Group 2 - Alkaline Earth Metals - 2nd most reactive elements. Also not “lone state” elements. Harder, denser than group 1. Common in sea salts.
Transition Metals - Groups 3-12. Harder, more brittle, higher melting point than groups 1 and 2. Form colored compounds. Conduct heat and electricity well and are shiny. Pd, Pt, Au - very unreactive (Noble metals). Tell stereo story.
Metalloids - B, Si, As, Te, At, Ge, Sb - stairs and 2 people under the stairs. Properties of metals and nonmetals. Brittle - used in semiconductors, computers.
Halogens - Group 17 - most reactive of the nonmetals. Not found free in nature. Solids, liquids, and gases in this group. Widespread - sea salts, minerals, living tissue. Many applications - bleach, photography, plastics, insecticides.
Noble Gases - Group 18 - Least reactive elements - used in air conditioners, double pane windows, lights, balloons.
Lanthanides - f block - rare earth elements - not really rare - shiny, silver, reactive, used to make TV’s glow.
Actinides - f block - unstable, radioactive - all but 4 are artificially created.
f block elements are called inner transition elements - they were put into their current position by Glenn Seaborg - the only living person ever to have an element named after him.
5.3Electron Configuration and Periodic Properties
Periodic Trends: For all of the following periodic trends you should:
a)know the definition
b)be able to draw the trend on small periodic table drawings with arrows
c)explain why the trend happens
d)relate the trend to other trends
e)apply the trends on an “AB” sheet
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1. Atomic Radius - basic idea is “ ” atoms are not spheres with outer boundaries due to the wave mechanical model.
kids make predictions
2 trendssize- natural, logical -
size- not logical! why?
from left to right - ______
______
trend looks like thisgraph looks like this
2. Electronegativity- basic idea - the ability of an atom to attract electrons (Linus Pauling)
Which atom attracts electrons better?
electronegativity is related to atomic size
trend looks like...trend looks like.....graph looks like...
3. Ionization energy - energy required to remove the most loosely held electron from the outer energy level of an atom.
A(g)+energyyieldsA+(g) +e-
trend looks like thisgraph looks like this
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IE is related to atomic radius - 2 reasons why smaller going down the table
1.
2.
There is also a 2nd and 3rd IE - always than the first. IE of elements greatly increases when the outer shell has been emptied.
which has a higher 2nd IE - Na or Mg? which has a higher 3rd IE - Al or Mg?
4. Electron Affinity - energy absorbed when an electron is acquired by a neutral atom.
Basic idea - some atoms want to take on electrons - they have a high electron affinity value - they receive a lot of energy when accepting electrons
examples:F = kJ/mole Na = kJ/mole
F has a higher electron affinity - higher, more negative value
general trend looks like this
5. Valence electrons - outer shell electrons involved with bonding.
Trend looks like
6. Ionic Radius - the size of an ion.
Ions are created by gaining or losing electrons.
Cation - positive, lost electronsAnion - negative, gained electrons
Metals tend to become cationsNonmetals tend to become anions
Cations are smaller than the neutral atom - why?
Anions are larger - why?
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trend looks like this....
examples: Li+1 or Be+2 - is bigger because
O -2 or N -3 - is bigger because
NIB Not in the Book
7. Activity (Reactivity)
for metals –l atoms are more active - why? - they electrons more easily
for nonmetals - more active - why? – they electrons more easily
metal activity trendnonmetal activity trend
Most active metals + most active nonmetals = most ______
ex: RbF - LiBr -
8. Metallic character- some metals are said to be more metallic than others - really it is just a statement about their activity. If they are more active, they are said to be more metallic.
trend looks like this...
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