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Memorize these element names & symbols:
Gases:
H hydrogen He helium Ne neon N nitrogen O oxygen F fluorine Cl chlorine Ar argon
Liquids:
Hg mercury Br bromine
Solids:
Li lithium B boron C carbon Na sodium Mg magnesiumAl aluminum Si silicon P phosphorusS sulfur K potassium Ca calciumCr chromium Mn manganese Fe ironCo cobalt Ni nickel Sn tinCu copper Zn zinc Pb leadAs arsenic I IodineSe selenium Ba bariumAg silver Au goldPt platinum U uranium
Arrangement of the Elements
Russian, Dmitri Mendeleev created The first “accepted” periodic table (1800’s)
1) Increasing atomic number
2) By groups or families:
columns
elements in a column have very similarproperties
3) periods
Rows (across)
Identify the element in:
Group 2A, period 4
Group 7A, period 5
Group 1 B, period 4
Ca
Cu
I
Properties of Metals
high melting pt. (not Hg)
shiny
good conductors of heat & electricity
malleable & ductile
easily oxidized:lose e- in chem rxns
Properties of Nonmetals
low melting pt. (sol, liq, gas)
poor conductors
solids are brittle & dull
gain e- in chem rxns
Reduction (easily reduced))
xenon
carbon sulfur
Properties of Metalloids (either side of zig zag line)
Ex: B, Si, Ge, As, Sb
not Al
properties are intermediate between metal and nonmetal
silicon
used in semiconductorindustry (computer chips)
5) Electron Arrangement
Apartment building analogyatom
apartment building
nucleus ground floor
energy levels floors
sublevels
apartments
orbitals
rooms
electrons
people
PrincipalQuantumNumber (n)
energy level
number ofsublevels
type of sublevels
number oforbitals
max number electrons
1 1 1 1s 1 2
2 2 2 2s 2p 4 8
3 3 3 3s 3p 3d 9 18
4 4 4 4s 4p 4d 4f 16 32
n2 2n2
Electron Configuration:The “address” of the e-
Ex: 1s22s22p6
energy level sublevel
no. electrons
1s2
2s2 2p6
3s2 3p6 3d10
4s2 4p6 4d10 4f14
5s2 5p6 5d10 5f14
6s2 6p6 6d10 6f14
7s2 7p6 7d10 7f14
Energy level
sublevels
max. no. e-
Sample problem:
Given the electron configuration: 1s22s22p63s23p5
1. How many electrons are unpaired?1
2. How many electrons are in the outermost energy level ? 7
3s23p5
3. How many energy levels and sublevels are occupied? 3 energy levels (1, 2, 3)
5 sublevels (1s 2s 2p 3s 3p)
4. What element has this ground state configuration? Cl
Given the configuration:
1s22s22p63s23p64s23d104p31. How many electrons are in the outer energy
level?5, 4s24p3
2. How many electrons are unpaired?3
this is the config.of: As
Short method for e- config.
Use noble gases
1st 10 e-
[Ne]
1st 18 e- [Ar]
1st 36 e- [Kr]
1st 54 e- [Xe]
1st 86 e- [Rn]
Ex: Cl17 e-
[Ne]3s2 3p5
Ex: Ba56e-
[Xe]6s2
Ex: Zn30 e-
[Ar] 4s2 3d10
Si
14 e-
[Ne] 3s23p2
U92 e-
[Rn]
7s2 5f4
Pd
46 e-
[Kr] 5s2 4d6
using the periodic table to write electron configurations
s & p
period # (n)12
34
56
7
6
7
d period #(n) -1
f Period #(n) -2
1s2s3s
2p
3p4s 4p5s 5p6s 6p7s
3d
4d
5d
6d
4f
5f
Ex: Na [Ne]3s1 Ex: P [Ne]3s23p3
Ex: Co [Ar] 4s23d7 Ex: Sn [Kr]5s24d10 5p2
Ex: Pu [Rn]7s2 4f6
1. calcium [Ar] 4s2
2. chlorine [Ne] 3s2 3p5
3. cadmium[Kr] 5s2 4d10
Families of ElementsA
lkali
meta
lsA
lkalin
e e
art
h
meta
ls Transition
metals
Inner transition
metals
Nob
le
gases
halo
gen
s
Group 1A: Alkali metals
Li
Na
K
Rb
Cs
Fr
1s2
2s1
[Ne] 3s1[Ar] 4s1
All have 1
valence electron
outer energy level
Na
most reactive metals
always found combined in nature
react with water producing hydrogen gas
Group 2A: Alkaline Earth Metals
BeMgCa
Sr
Ba
Ra
1s2 2s2
[Ne]3s2
[Ar] 4s2
Mg
all have 2 valence electrons
quite reactive; always found combined w/ other elements in nature
Also react w/ water to produce
hydrogen gas
Group 7A: Halogens
F
Cl
Br
I
At
1s2 2s2 2p5
[Ne] 3s2 3p5 [Ar] 4s2 3d10 4p5
most reactive nonmetals
all have 7 valence e-
always found in compounds
form salts whencombined withmetals; ex: NaCl, KI
Cl
Group 8 A: Noble Gases
HeNeAr
Kr
Xe
Rn
1s2
1s2 2s2 2p6
[Ne] 3s2 3p6
most have 8 valence e-
Xe
chemically inert (unreactive);
don’t form compoundsfilled
outer levels makes them stable
Kr
Ar
Transition Metals
(B groups)
“typical” metals
unique property: form bright colored compounds
Au
Ag
Inner Transition elements
actinides serieslanthanide
series
Ac
La
many are synthetic (man made)
and radioactive
“yellow cake” uranium oxide
Trend: property that changes
Group
trend
change from top to bottom down a group
atomic radius, ionization energy, electronegativity
Periodic trend
Change from left to right across the row
I. Atomic Radius Indicates the size of an atom
Group trend
larger down the group
more energy levels makes the atoms larger
Li: 2 energy levels
K: 4 energy levels
Periodic trend
smaller acrossmore protons increases nuclear charge; pulls electrons in closer making the atom smaller
Li C Ne
+3
+6
+10arrange these atoms
from smallest to largest: Sr, Ne, Ca, S, Al
Ne S Al Ca Sr
III. Ionization Energy
Energy required to remove an e- from an atom
Group trenddecreases going
down
larger atoms hold their valence e- more loosely
Li
K
Periodic trend
Increases across; increase in nuclear charge (more p+) causeselectrons to be held more tightly
Na
+11
+13
Al Cl
+17
Ex: Which will lose an electron the easiest?
K or Ge ?
Mg or Ba ? Al or Cs ?
IV. Electronegativit
y
Number from 0-4 that indicates an atom’s attraction for e-
F 4.0
gains e- easily; very
reactive
Cs 0.7
loses e-
easily;very reactivegrou
p tren
ddecreases going down
Periodic trend
Increases going across (not noble gases
Ex: Arrange these atoms from greatest attraction for e- to least: P, Al, Sr, O O, P, Al, Sr