Name:_________________________________ Period:_________
UNIT #3: Electrons in Atoms/Periodic Table and Trends
1. ELECTRON CONFIGURATION
Electrons fill the space surrounding an atom’s nucleus in a very specific order following the rules listed below:
a) Aufbau Principle: Each electron occupies the lowest energy orbital available. The orbitals closest to the nucleus have the lowest energy; the orbitals farthest from the nucleus have the highest energy.
Order of increasing energy: 1s→2s→2p→3s→3p→4s→3d→4p→5s→4d→5p→6s→4f→5d→6p→7s→5f→6d→7p
b) Pauli Exclusion Principle: A maximum of two electrons may occupy a single orbital, but only if the electrons have opposite spins. Each electron in an atom has an associated spin, similar to the way a top spins on its axis. Like a top, an electron can spin in only one of two directions. In an orbital diagram, this is represented by an arrow up ↑ for an electron spinning in one direction, and an arrow down ↓ for an electron spinning in the opposite direction.
c) Hund’s Rule: Single electrons with the same spin must occupy each equal-energy orbital before additional electrons with opposite spins can occupy the same orbitals. This is due to the fact that electrons carry like negative charges and thus, repel each other. An electron will pair up with another electron within a given sublevel (s,p,d,f) only when necessary and in doing so, adopts the opposite spin.
Key Terms: 1. Principle Energy/Quantum Level: Major energy levels surrounding the nucleus of an atom. Consists of n=1, n=2, n=3, n=4, n=5, n=6, n=7 (corresponding to periods 1 through 7 on the periodic table).
2. Energy Sublevels: Within a principle energy level, electrons occupy sublevels labeled s, p, d or f according to the shape of the atom’s orbital. S-orbitals are spherical in shape; p- orbitals are dumbbell shaped; d and f orbitals have varying shapes.
3. Orbitals: Within a sublevel, electrons occupy a specific number of orbitals, each of which contain up to one pair of electrons with opposite spins. The number of orbitals within a sublevel is as follows: S-sublevel: Contains one orbital which contains a maximum of 2 electrons. P-sublevel: Contains three orbitals, each of which contains a maximum of 2 electrons. Maximum number of p-sublevel electrons is six. D-sublevel: Contains five orbitals, each of which contains a maximum of 2 electrons. Maximum number of d-sublevel electrons is ten. F-sublevel: Contains seven orbitals, each of which contains a maximum of 2 electrons. Maximum number of f-sublevel electrons is fourteen.
4. Valence Electrons: Electrons occupying the outermost principle energy level.
2
Electron Configuration: Denotes the filling of electrons according to the rules listed above. The configurations depict the principle energy level of each electron (coefficient 1 through 7), followed by the sublevel (s,p,d,f), followed by a superscript that represents the number of electrons. NOTE: Electrons filling sublevel d drop one energy level and electrons filling sublevel f drop two energy levels.
Order of filling sublevels according to aufbau principle: Period 1 atoms: 1s Period 2 atoms: 1s, 2s, 2p Period 3 atoms: 1s, 2s, 2p, 3s, 3p Period 4 atoms: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p Period 5 atoms: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p Period 6 atoms: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p Period 7 atoms: 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f, 6d, 7p
Ex. He: 1s2 (2 electrons in atom) Ne: 1s22s22p6 (10 electrons in atom) Ar: 1s22s22p63s23p6 (18 electrons in atom) Kr: 1s22s22p63s23p64s23d104p6 (36 electrons in atom) Xe: 1s22s22p63s23p64s23d104p65s24d105p6 (54 electrons in atom) Rn: 1s22s22p63s23p64s23d104p65s24d105p66s24f145d106p6 (86 electrons in atom) NOTE: In these examples, each atom (other than helium) contains 8 valence electrons. This is the stable octet that all other atoms strive to achieve. When atoms become ions, they either lose electrons (metals) or gain electrons (non-metals) to achieve a stable principle energy level similar to their closest noble gas.
More examples of neutral atoms versus their corresponding ions: Be 1s22s2 neutral beryllium atom with 4 electrons Be2+ 1s2 beryllium ion with 2 electrons (lost 2)
Na 1s22s22p63s1 neutral atom with 11 electrons Na+ 1s22s22p6 sodium ion with 10 electrons (lost 1)
O 1s22s22p4 neutral oxygen atom with 8 electrons O2- 1s22s22p6 oxide ion with 10 electrons (gained 2)
P 1s22s22p63s23p3 neutral phosphorous atom with 15 electrons P3- 1s22s22p63s23p6 phosphide ion with 18 electrons (gained 3) Orbital Diagrams: Denotes each orbital within a sublevel and the electrons occupying those orbitals (indicated by an up arrow ↑ or a down arrow ↓). Electrons fill orbitals singularly at first, then pair as necessary with an opposite spin. Ex. 2p4 ↑↓ ↑ ↑ 2p 2p 2p 3d7 ↑↓ ↑↓ ↑_ ↑_ ↑_ 3d 3d 3d 3d 3d
3
2. ELEMENTS AND THE PERIODIC TABLE
a) An element is a pure substance that cannot be separated into simpler substances by physical or chemical means.
b) Each element has a unique chemical name and symbol. The chemical symbol consists of one, two or three letters: the first letter is always capitalized and the remaining letter(s) are always lowercase.
c) Seven elements occur in nature as diatomic molecules (2 atoms) because the molecules formed are more stable than the individual atoms. They are Br2, I2, N2, Cl2, H2, O2, F2. Remember it as BrINClHOF.
d) On earth, 91 elements are naturally occurring and their abundance in the universe varies. e) The Periodic Table organizes the elements according to increasing atomic number.
1. Elements are arranged in vertical columns called groups or families. Each group is numbered 1 through 18.
2. Groups 1, 2, 13, 14, 15, 16, 17 and 18 are often referred to as the main group, or representative elements, because they possess a wide range of chemical and physical properties.
3. Groups 3, 4, 5, 6, 7, 8, 9, 10, 11 and 12 are referred to as the transition elements. 4. Elements in the same group have similar chemical and physical properties.
5. Elements are arranged in horizontal rows called periods. Beginning with hydrogen in period 1, there are a total of 7 periods.
f) Classification of Elements 1. Metals are elements that are generally shiny when smooth and clean, solid at room
temperature, and good conductors of heat and electricity. Most metals are malleable (can be pounded into thin sheets) and ductile (can be drawn into wires).
a) Used to transmit electrical power, ex. copper. b) Can be formed into coins, tools, fasteners and wires. c) Group 1 elements (except hydrogen) are known as the alkali metals.
d) Group 2 elements are known as the alkaline earth metals. e) Both alkali and alkaline earth metals are chemically reactive, with alkali
metals being the more reactive group. f). Groups 3 through 12 elements are divided into 1. transition metals-located in periods 4 through 7. 2. inner transition metals-two sets of inner transition metals, known as the
lanthanide and actinide series, appear at the bottom of the periodic table and are usually offset from the numbered periods. These elements are phosphors, substances that emit light when struck by electrons.
2. Nonmetals are elements that are generally gases or brittle, dull-looking solids. They are poor conductors of heat and electricity. The only non-metal that is a liquid at room temperature is bromine.
a) Group 17 elements are the halogens. These are the most reactive non-metals. b) Group 18 elements are the noble gases-extremely unreactive due to the most
stable and complete electron configuration. 3. Metalloids or semimetals are elements with physical and chemical properties of both
metals and nonmetals. a) Located on the right hand side of the periodic table and form a stair-step
pattern between the transition metals and the nonmetals. b) Consists of B, Si, Ge, As, Sb, Te and At.
4
3. COMPOUNDS AND LAWS OF DEFINITE/MULTIPLE PROPORTI ONS
a) A compound is a combination of two or more different elements that are combined chemically. Much of the matter of the universe are compounds; there are approximately 10 million known compounds.
Examples are water, table salt, table sugar, aspirin. b) Compounds or elements that occur alone are referred to as pure substances. Compounds
or elements that occur in combination with other compounds or elements are referred to as mixtures. 1. Homogenous mixture-one that has a uniform composition throughout and always has
a single phase; can be separated by physical means such as distillation (a technique used to separate mixtures based on the differences in the boiling points of the substances) or by evaporation (removing liquid component from solid component); homogenous mixtures are also referred to as solutions.
Ex. salt water, sugar water, lemonade, gasoline, steel. 2. Heterogeneous mixture-one that does not have a uniform composition and in which
the individual substances remain distinct; can be separated by physical means such as filtration (technique that uses a porous barrier to separate solids from liquids). Ex. sand and water, dirt, Italian salad dressing.
c) Law of Definite Proportions 1. Elements making up compounds always combine in definite proportions by mass.
Regardless of the amount of a given compound, it is always composed of the same elements in the same proportion by mass.
d) Law of Multiple Proportions 1. When different compounds are formed by combinations of the same elements,
different masses of one element combine with the same relative mass of the other element in a ratio of small whole numbers.
2. Examples: a) Water is H2O: 2 parts hydrogen to 1 part oxygen Hydrogen Peroxide is H2O2: 2 parts hydrogen to 2 parts oxygen Both compounds are comprised of the same elements; however, H2O2 differs from
H2O in that it has twice as much oxygen. When we compare the mass of oxygen in H2O2 to the mass of oxygen in H2O, we get the ratio 2:1.
b) Methane is CH4; Carbon = 12amu and Hydrogen = 4amu; Cmass : Hmass = 12:4 or 3:1 Ethane is C2H6; Carbon = 24amu and Hydrogen = 6amu; Cmass : Hmass = 24:6 or 4:1
4. PERIODIC TABLE TRENDS
a) Atomic Radius 1. The radius of an atom is one-half the distance between the nuclei of two atoms of the
same element when the atoms are joined; it is comparable to the radius of a circle which is the length of a line from the center of the circle to its edge.
2. Radius decreases as you move across a period. As you move across a period, each successive element has one additional proton in its nucleus; therefore, the positive nuclear pull increases on the negative electrons surrounding the nucleus, causing the radius to decrease.
5
3. Radius increases as you move down a group. As you move down a group, each successive element has an additional energy level surrounding its nucleus and therefore, the radius increases.
b) Ionic Radius 1. An ion is an atom or a bonded group of atoms that has a positive charge (due to loss of
electrons) or negative charge (due to gaining electrons). 2. When atoms lose electrons to become positive ions, their radius decreases. The loss
of valence electrons from the outermost energy level results in an empty valence shell and therefore, the next level down becomes the ion’s outermost energy level; therefore, the radius decreases.
3. When atoms gain electrons to become negative ions, their radius increases. The addition of electron(s) to the outermost energy level results in additional repulsive forces between the like-charged electrons. This causes the electrons to move further apart and effectively, increases the ion’s radius.
c) Ionization Energy 1. Ionization energy is the energy required to remove an electron from a gaseous atom. It
is an indication of how strongly the atom’s nucleus is pulling on its electrons. A higher ionization energy value means more energy is required to remove an electron, indicating a strong nuclear pull. A lower ionization energy value means less energy is required to remove an electron, indicating a weaker nuclear pull.
2. Ionization energy increases as you move across a period. As the number of protons increases across a period, the nuclear pull increases.
3. Ionization energy decreases as you move down a group. As energy levels are added moving down a group, the valence electrons become farther removed from the nuclear pull and its effect decreases. Also, an increase in the number of electrons between the outermost energy level and the nucleus causes what is termed a “shielding effect,” that is, the nuclear pull is diminished due to the intervening electrons.
d) Electronegativity 1. Electronegativity indicates the ability of an atom to attract electrons in a chemical bond. 2. Electronegativity increases as you move across a period. An increase in the number
of protons in the nucleus of each successive atom results in a stronger nuclear pull on the atom’s own electrons and on another atom’s electrons in a chemical bond.
3. Electronegativity decreases as you move down a group. An increase in the distance between the nucleus and the outermost electrons results in a weaker nuclear pull on the atom’s own electrons and on another atom’s electrons in a chemical bond.
Ad
apte
d a
nd
mo
dif
ied
fro
m J
oh
n G
eld
er’s
DR
AF
T V
ER
SIO
N.
Dev
elo
pin
g t
he C
on
cep
t o
f S
hell
s, S
ub
shell
s, E
lectr
on
Co
nfi
gu
ra
tio
ns,
an
d M
ore
PA
RT
I:
Dis
cove
ring
ho
w e
lect
rons
are
‘a
rra
ng
ed’
in a
n a
tom
1.
Des
crib
e th
e n
atu
re o
f th
e in
tera
ctio
n b
etw
een
pro
ton
s an
d e
lect
ron
s in
an
ato
m?
Co
nsi
der
usi
ng
so
me
or
all
of
the
foll
ow
ing
ter
ms
in y
ou
r d
escr
ipti
on
:
•
attr
acti
on
, re
pu
lsio
n,
neu
tral
, p
osi
tiv
e, n
egat
ive,
ch
arg
e, d
ista
nce
, n
ucl
eus,
forc
e, e
ner
gy
, C
ou
lom
b’s
Law
.
2.
Fo
r ea
ch s
itu
atio
n b
elo
w,
com
par
e th
e re
lati
ve
ener
gy
nec
essa
ry t
o s
epar
ate
po
siti
ve
and
neg
ativ
e el
ectr
ical
ch
arg
es.
•
Co
mp
are
A t
o B
•
Co
mp
are
A t
o C
Ad
apte
d a
nd
mo
dif
ied
fro
m J
oh
n G
eld
er’s
DR
AF
T V
ER
SIO
N.
3.
Co
nsi
der
•
Ho
w m
any
ele
ctro
ns
do
yo
u s
ee i
n t
he
pic
ture
? H
ow
man
y p
roto
ns?
•
Wh
ich
of
thes
e el
ectr
on
s is
th
e ea
sies
t (r
equ
ires
th
e le
ast
amo
un
t o
f
ener
gy
) to
rem
ov
e (i
on
ize)
? Ju
stif
y y
ou
r an
swer
.
•
Co
mp
are
the
ener
gy
req
uir
ed t
o r
emo
ve
the
elec
tro
n f
rom
3 w
ith
th
e
ener
gy
in
•
2a
•
2c
Th
e fi
rst
ion
izat
ion
en
erg
y i
s d
efin
ed a
s th
e m
inim
um
en
erg
y t
hat
mu
st b
e ad
ded
to
a
neu
tral
ato
m,
in t
he
gas
ph
ase,
to
rem
ov
e an
ele
ctro
n f
rom
th
at a
tom
.
Th
is d
efin
itio
n c
an b
e re
pre
sen
ted
by
th
e fo
llo
win
g c
hem
ical
eq
uat
ion
:
ener
gy
+ A
(g) →
A+(g
) +
e–
4.
In t
he
ion
izat
ion
eq
uat
ion
ab
ov
e id
enti
fy w
hic
h s
pec
ies
is a
t lo
wer
en
erg
y,
A(g
) o
r A
+(g
) +
e–?
Ju
stif
y y
ou
r an
swer
.
5.
Exp
lain
wh
y e
ner
gy
is
req
uir
ed (
an e
nd
oth
erm
ic p
roce
ss)
to r
emo
ve
the
elec
tro
n
in a
neu
tral
ato
m.
6.
Th
e v
alu
e o
f th
e fi
rst
ion
izat
ion
en
erg
y f
or
hy
dro
gen
is
13
12
kJ
mo
l-1.
ener
gy
+ H
(g) →
H+(g
) +
e–
On
th
e g
rap
h o
n t
he
nex
t p
age
use
a s
ho
rt h
ori
zon
tal
lin
e to
in
dic
ate
the
ener
gy
of
H(g
) an
d a
sh
ort
ho
rizo
nta
l li
ne
to i
nd
icat
e th
e en
erg
y o
f H
+(g
) +
e–. B
e su
re t
o
con
sid
er y
ou
r re
spo
nse
s to
Q4
an
d Q
5 a
bo
ve.
!
Ad
apte
d a
nd
mo
dif
ied
fro
m J
oh
n G
eld
er’s
DR
AF
T V
ER
SIO
N.
7.
Wh
at d
oes
th
e d
iffe
ren
ce i
n e
ner
gy
in
th
e li
nes
in
yo
ur
dia
gra
m a
bo
ve
rep
rese
nt?
Th
e v
alu
es f
or
the
firs
t io
niz
atio
n e
ner
gy
fo
r a
hy
dro
gen
an
d h
eliu
m a
tom
are
pro
vid
ed i
n
the
tab
le b
elo
w.
!
Ato
m
1H
2H
e 3L
i
Ion
izat
ion
En
erg
y (
kJ
mo
l –
1)
13
12
2
37
3
!
8.
Bas
ed o
n c
om
par
iso
ns
yo
u m
ade
in Q
ues
tio
n 2
ho
w w
ou
ld y
ou
exp
lain
th
e
dif
fere
nce
in
th
e v
alu
es f
or
the
firs
t io
niz
atio
n e
ner
gy
fo
r h
yd
rog
en a
nd
hel
ium
?
9.
Ho
w d
oes
yo
ur
exp
lan
atio
n a
cco
un
t fo
r th
e re
lati
ve
char
ge
on
hy
dro
gen
an
d
hel
ium
an
d t
he
dis
tan
ce o
f th
e el
ectr
on
(s)
fro
m t
he
nu
cleu
s?
H(g
) H
+(g
) +
e–
Ad
apte
d a
nd
mo
dif
ied
fro
m J
oh
n G
eld
er’s
DR
AF
T V
ER
SIO
N.
In t
he
ener
gy
dia
gra
m b
elo
w l
oca
te (
dra
w a
ho
rizo
nta
l li
ne)
th
e fi
rst
ion
izat
ion
en
erg
y f
or
hy
dro
gen
an
d t
he
firs
t io
niz
atio
n e
ner
gy
fo
r h
eliu
m.
10
. H
ow
do
es t
he
dia
gra
m i
llu
stra
te t
he
rela
tiv
e ea
se w
ith
wh
ich
an
ele
ctro
n c
an b
e
rem
ov
ed f
rom
eac
h a
tom
?
11
. P
red
ict
a v
alu
e fo
r th
e fi
rst
ion
izat
ion
en
erg
y f
or
lith
ium
.
Do
no
t ad
d y
ou
r p
red
icti
on
to
th
e fi
gu
re j
ust
yet
. Ju
stif
y y
ou
r p
red
icti
on
(lo
ok
bac
k a
t Q
ues
tio
n 2
if
yo
u n
eed
gu
idan
ce).
Ad
apte
d a
nd
mo
dif
ied
fro
m J
oh
n G
eld
er’s
DR
AF
T V
ER
SIO
N.
Th
e ac
tual
val
ue
of
the
firs
t io
niz
atio
n e
ner
gy
of
lith
ium
is
52
0 k
J m
ol-1
. A
dd
th
is v
alu
e
for
to t
he
fig
ure
on
th
e p
rev
iou
s p
age.
12
. H
ow
wo
uld
yo
u e
xp
lain
th
e io
niz
atio
n e
ner
gy
fo
r li
thiu
m c
om
par
ed t
o t
he
ion
izat
ion
en
erg
y f
or
hel
ium
? C
om
par
ed t
o h
yd
rog
en?
13
. P
red
ict
the
rela
tiv
e v
alu
e o
f th
e en
erg
y n
eces
sary
to
rem
ov
e a
seco
nd
ele
ctro
n
(cal
led
th
e se
con
d i
on
izat
ion
en
erg
y)
fro
m l
ith
ium
. S
up
po
rt y
ou
r p
red
icti
on
wit
h
an e
xp
lan
atio
n.
14
. B
ased
on
th
e fi
rst
ion
izat
ion
en
erg
ies
for
hy
dro
gen
, h
eliu
m a
nd
lit
hiu
m t
hat
yo
u
rep
rese
nte
d i
n t
he
fig
ure
on
th
e p
rev
iou
s p
age,
wh
at c
an y
ou
in
fer
abo
ut
the
dis
tan
ce o
f th
e el
ectr
on
s fr
om
th
eir
resp
ecti
ve
nu
clei
.
! ! ! ! Th
e fi
rst
ion
izat
ion
en
erg
ies
for
sele
cted
ele
men
ts f
rom
th
e se
con
d p
erio
d o
f th
e p
erio
dic
tab
le a
re p
rov
ided
in
th
e ta
ble
bel
ow
.
Ato
m
3L
i 4B
e 6C
7N
9F
1
0N
e
Ion
izat
ion
En
erg
y (
kJ
mo
l –
1)
52
0
89
9
10
86
1
30
2
16
81
2
08
1
15
. E
xp
lain
th
e tr
end
in
io
niz
atio
n e
ner
gie
s in
ter
ms
of
the
char
ge
of
the
nu
cleu
s an
d
the
rela
tiv
e lo
cati
on
of
the
elec
tro
ns.
Th
e fi
rst
ion
izat
ion
en
erg
y f
or
the
elem
ent
sod
ium
is
giv
en i
n t
he
foll
ow
ing
tab
le.
Ato
m
11N
a 1
2M
g
14S
i 1
5P
1
7C
l 1
8A
r
Ion
izat
ion
En
erg
y (
kJ
mo
l –
1)
52
0
16
. P
red
ict
the
val
ues
fo
r th
e fi
rst
ion
izat
ion
en
erg
y f
or
the
oth
er s
elec
ted
th
ird
per
iod
elem
ents
. E
xp
lain
ho
w y
ou
arr
ived
at
yo
ur
pre
dic
tio
ns.
Ad
apte
d a
nd
mo
dif
ied
fro
m J
oh
n G
eld
er’s
DR
AF
T V
ER
SIO
N.
Bel
ow
is
a ta
ble
co
nta
inin
g t
he
elec
tro
n e
ner
gie
s fo
r ea
ch o
f th
e 1
8 e
lect
ron
s in
an
arg
on
ato
m.
Th
e g
rap
h o
f th
is d
ata
is s
ho
wn
.
17
. M
ake
ob
serv
atio
ns
abo
ut
the
gra
ph
in
ter
ms
of
the
rela
tiv
e en
erg
ies
of
the
elec
tro
ns
and
th
eir
rela
tio
nsh
ip t
o e
ach
oth
er.
18
. B
ased
on
yo
ur
resp
on
ses
fro
m t
he
pre
vio
us
qu
esti
on
s h
ow
man
y ‘
gro
up
s’ (
lev
els
or
shel
ls)
of
elec
tro
ns
are
sho
wn
fo
r A
rgo
n?
19
. In
dic
ate
the
nu
mb
er o
f el
ectr
on
s in
eac
h g
roup
/lev
el t
hat
yo
u i
den
tifi
ed?
Ele
ctro
n
Rem
ov
ed
Ele
ctro
n
En
erg
y
(kJ
mo
l –
1)
1
−1
52
1
2
−2
66
6!
3
−3
93
1!
4
−5
75
1!
5
−7
23
8!
6
−8
78
1!
7
−1
19
95!
8
−1
38
42!
9
−4
07
60!
10
−
46
18
6!
11
−
52
00
2!
12
−
59
65
3!
13
−
66
19
8!
14
−
72
91
8!
15
−
82
47
2!
16
−
88
57
6!
17
−
39
76
04!
18
−
42
70
65!
Ad
apte
d a
nd
mo
dif
ied
fro
m J
oh
n G
eld
er’s
DR
AF
T V
ER
SIO
N.
20
. O
n t
he
gra
ph
bel
ow
dra
w a
ho
rizo
nta
l li
ne
(to
th
e ri
gh
t o
f th
e y
-ax
is)
that
rep
rese
nts
an
av
erag
e en
erg
y l
evel
fo
r ea
ch o
f th
e g
roup
s o
f el
ectr
on
s th
at y
ou
iden
tifi
ed.
Lab
el t
he
lev
els
1,
2,
etc.
… b
egin
nin
g f
rom
th
e lo
wes
t en
erg
y l
evel
.
Wh
at d
o t
hes
e li
nes
rep
rese
nt?
2
1. H
ow
wo
uld
yo
u d
escr
ibe
the
rela
tiv
e en
erg
y s
epar
atio
n o
f th
ese
ener
gy
lev
els?
22
. A
n e
lect
ron
fro
m w
hic
h l
evel
req
uir
es
•
the
least
am
ou
nt
of
ener
gy
to
rem
ov
e?
•
Th
e la
rges
t am
ou
nt
of
ener
gy
to
rem
ov
e?
Ad
apte
d a
nd
mo
dif
ied
fro
m J
oh
n G
eld
er’s
DR
AF
T V
ER
SIO
N.
Des
crib
e th
e el
ectr
on
str
uct
ure
(lo
cati
on
of
the
elec
tro
n)
of
the
ato
m.
Co
nsi
der
usi
ng
som
e o
r al
l o
f th
e fo
llo
win
g t
erm
s in
yo
ur
des
crip
tio
n;
nu
cleu
s, e
lect
ron
, en
erg
y,
dis
tan
ce,
lev
el, p
roto
n,
shel
l, a
rran
gem
ent,
att
ract
ion
, re
pu
lsio
n, p
osi
tiv
e, n
egat
ive,
ch
arg
e,
loca
tio
n.
PA
RT
II:
Do
all
ele
ctro
ns
in t
he
sam
e le
vel
ha
ve t
he
sam
e en
erg
y?
On
e im
po
rtan
t co
ncl
usi
on
bas
ed o
n t
he
firs
t io
niz
atio
n e
ner
gy
exp
erim
enta
l d
ata
is t
hat
elec
tro
ns
in h
igh
er s
hel
ls r
equ
ire
less
en
erg
y t
o r
emo
ve.
We
hav
e ex
amin
ed e
xp
erim
enta
l
dat
a th
at r
elat
es t
he
ener
gy
req
uir
ed t
o r
emo
ve
an e
lect
ron
to
th
e sh
ell
the
elec
tro
n
occ
up
ies.
•
In w
hic
h s
hel
l d
oes
an
ele
ctro
n r
equ
ire
mo
re e
ner
gy
to
rem
ov
e, a
n e
lect
ron
in
th
e
seco
nd
sh
ell
or
the
fou
rth
sh
ell?
An i
nte
rest
ing
qu
esti
on
th
at c
ann
ot
be
answ
ered
fro
m t
he
exp
erim
enta
l d
ata
of
the
firs
t
ion
izat
ion
en
erg
y i
s…
Do
all
ele
ctro
ns
in t
he
sam
e sh
ell
req
uir
e th
e sa
me
am
ou
nt
of
ener
gy
to r
emo
ve?
We
CA
N a
nsw
er t
his
qu
esti
on
if
we
loo
k a
t p
ho
toel
ectr
on
sp
ectr
osc
op
y (
PE
S)
dat
a fo
r
the
ato
ms.
In
a p
ho
toel
ectr
on
sp
ectr
osc
op
y e
xp
erim
ent
any
ele
ctro
n c
an b
e io
niz
ed w
hen
the
ato
m i
s ex
cite
d.
Lik
e w
ith
th
e fi
rst
ion
izat
ion
, o
nly
on
e el
ectr
on
is
rem
ov
ed f
rom
th
e
ato
m.
Ho
wev
er i
n a
PE
S e
xp
erim
ent
it c
an b
e A
NY
ele
ctro
n,
no
t ju
st t
he
elec
tro
n t
hat
req
uir
es t
he
leas
t am
ou
nt
of
ener
gy
to
rem
ov
e.
Ad
apte
d a
nd
mo
dif
ied
fro
m J
oh
n G
eld
er’s
DR
AF
T V
ER
SIO
N.
Ex
amin
e th
e P
ES
sp
ectr
um
fo
r h
yd
rog
en s
ho
wn
in
th
e fi
gu
re.
Th
e la
bel
on
th
e y-a
xis
is
ener
gy
an
d t
he
un
its
are
in m
egaj
ou
les(
M J
mo
l –
1)
1.
Wh
at d
oes
th
e x-a
xis
dep
ict?
Exp
lain
.
Ad
apte
d a
nd
mo
dif
ied
fro
m J
oh
n G
eld
er’s
DR
AF
T V
ER
SIO
N.
2.
Wh
at i
s th
e re
lati
on
ship
bet
wee
n t
he
ph
oto
elec
tro
n s
pec
tru
m a
nd
th
e fi
rst
ion
izat
ion
en
erg
y f
or
hy
dro
gen
?
Hel
ium
is
nex
t, b
ut
bef
ore
lo
ok
ing
at
its
ph
oto
elec
tro
n s
pec
tru
m a
nsw
er t
he
foll
ow
ing
qu
esti
on
s:
3.
Ho
w m
any
ele
ctro
ns
do
es h
eliu
m h
ave
in i
ts f
irst
sh
ell?
4.
Ref
er b
ack
to
Par
t I
of
this
act
ivit
y,
and
ob
tain
th
e fi
rst
ion
izat
ion
en
erg
y f
or
a
hel
ium
ato
m.
Can
yo
u p
red
ict
wh
at t
he
PE
S w
ou
ld l
oo
k l
ike
if
a.
the
sam
e am
ou
nt
of
ener
gy
is
req
uir
ed t
o r
emo
ve
each
of
the
elec
tro
ns?
b.
dif
fere
nt
amo
un
ts o
f en
erg
y a
re r
equ
ired
to
rem
ov
e ea
ch e
lect
ron
?
Go
to
bac
k t
o t
he
pre
vio
us
fig
ure
an
d s
ket
ch b
oth
sce
nar
ios.
Ad
apte
d a
nd
mo
dif
ied
fro
m J
oh
n G
eld
er’s
DR
AF
T V
ER
SIO
N.
Ex
amin
e th
e P
ES
fo
r h
eliu
m a
nd
co
mp
are
it t
o y
ou
r p
red
icti
on
fro
m t
he
pre
vio
us
qu
esti
on
.
5
. E
xp
lain
th
e re
lati
ve
ener
gy
of
the
pea
k(s
) an
d t
he
nu
mb
er o
f el
ectr
on
s re
pre
sen
ted
by
eac
h p
eak
in
th
e P
ES
fo
r h
eliu
m a
nd
fo
r h
yd
rog
en.
6.
Fo
r li
thiu
m
a.
Ho
w m
any
ele
ctro
ns
do
es l
ith
ium
hav
e?
b.
Wh
at s
hel
ls (
lev
els)
do
th
ose
ele
ctro
ns
occ
up
y?
7.
Pre
dic
t w
hat
yo
u e
xp
ect
the
PE
S f
or
lith
ium
to
lo
ok
lik
e. (
No
te:
yo
u d
o n
ot
hav
e
to p
red
ict
the
exac
t en
erg
ies
of
each
ele
ctro
n,
yo
u c
an m
ake
a re
aso
nab
le e
stim
ate
bas
ed o
n t
he
firs
t io
niz
atio
n e
ner
gie
s fo
r li
thiu
m a
nd
hel
ium
- r
efer
bac
k t
o P
art
I
of
this
act
ivit
y.
Ad
apte
d a
nd
mo
dif
ied
fro
m J
oh
n G
eld
er’s
DR
AF
T V
ER
SIO
N.
L
oo
k a
t th
is P
ES
an
d c
om
par
e it
to
th
e p
red
icti
on
yo
u m
ade
in t
he
pre
vio
us
qu
esti
on
.
8.
Fo
r ea
ch p
eak
in
th
e P
ES
of
lith
ium
, id
enti
fy t
he
shel
l th
e el
ectr
on
s re
pre
sen
ted
by
that
pea
k o
ccup
y.
Be
sure
to
co
mm
ent
abo
ut
the
rela
tiv
e en
erg
y o
f th
e p
eak
(s)
and
the
nu
mb
er o
f el
ectr
on
s fo
r ea
ch p
eak
fo
r L
i.)
Th
e n
ext
elem
ent
in t
he
Per
iod
ic T
able
is
ber
yll
ium
.
9.
Ho
w m
any
ele
ctro
ns
do
es b
ery
lliu
m h
ave
and
wh
at s
hel
ls d
o t
ho
se e
lect
ron
s
occ
up
y?
10
. F
or
the
PE
S f
or
ber
yll
ium
pre
dic
t
a.
ho
w m
any
pea
ks
b.
the
nu
mb
er o
f el
ectr
on
fo
r ea
ch p
eak
c.
esti
mat
e th
e re
lati
ve
ener
gie
s.
Ad
apte
d a
nd
mo
dif
ied
fro
m J
oh
n G
eld
er’s
DR
AF
T V
ER
SIO
N.
T
he
nex
t el
emen
t in
th
e P
erio
dic
Tab
le i
s b
oro
n.
11
. H
ow
man
y e
lect
ron
s d
oes
bo
ron
hav
e an
d w
hat
sh
ells
do
th
ose
ele
ctro
ns
occ
up
y?
12
. F
or
the
PE
S f
or
bo
ron
pre
dic
t
a.
ho
w m
any
pea
ks
b.
the
nu
mb
er o
f el
ectr
on
(s)
for
each
pea
k
c.
esti
mat
e th
e re
lati
ve
ener
gie
s
Ad
apte
d a
nd
mo
dif
ied
fro
m J
oh
n G
eld
er’s
DR
AF
T V
ER
SIO
N.
Bel
ow
is
the
PE
S f
or
bo
ron
.
13
. B
rief
ly d
escr
ibe
ho
w t
o i
nte
rpre
t th
e P
ES
fo
r b
oro
n.
14
. P
red
ict
wh
at c
han
ges
in
th
e P
ES
yo
u w
ou
ld e
xp
ect
to s
ee g
oin
g a
cro
ss p
erio
d 2
of
the
per
iod
ic t
able
, fr
om
car
bo
n t
o n
eon
? L
oo
k a
t th
e P
ES
fo
r th
ese
seco
nd
per
iod
elem
ents
.
Ad
apte
d a
nd
mo
dif
ied
fro
m J
oh
n G
eld
er’s
DR
AF
T V
ER
SIO
N.
Bel
ow
is
the
PE
S f
or
the
per
iod
2 e
lem
ents
fro
m b
oro
n t
o n
eon
.
Ad
apte
d a
nd
mo
dif
ied
fro
m J
oh
n G
eld
er’s
DR
AF
T V
ER
SIO
N.
15
. A
nsw
er t
he
foll
ow
ing
qu
esti
on
s af
ter
loo
kin
g a
t th
e P
ES
fo
r h
yd
rog
en t
hro
ug
h
neo
n. a.
Wo
uld
yo
u a
gre
e o
r d
isag
ree
wit
h t
he
foll
ow
ing
sta
tem
ent?
Exp
lain
yo
ur
answ
er.
‘Th
e el
ectr
ons
in t
he
seco
nd
sh
ell
all
ha
ve t
he
sam
e en
erg
y.’
b.
Ho
w m
any
‘su
bsh
ells
’ ar
e fo
un
d i
n t
he
seco
nd
sh
ell?
c.
Ho
w m
any
‘su
bsh
ells
’ ar
e fo
un
d i
n t
he
firs
t sh
ell?
d.
Ho
w m
any
ele
ctro
ns
are
in e
ach
sub
shel
l in
th
e se
con
d s
hel
l? I
n t
he
firs
t
shel
l?
e.
Mo
vin
g s
yst
emat
ical
ly f
rom
lit
hiu
m t
o n
eon
;
i.
Ho
w m
any
ele
ctro
ns
are
in t
he
firs
t sh
ell?
ii.
Wh
at h
app
ens
to t
he
ener
gy
req
uir
ed t
o r
emo
ve
an e
lect
ron
in
th
e
firs
t sh
ell
mo
vin
g f
rom
lef
t to
rig
ht
in t
he
seco
nd
per
iod
? S
up
po
rt
yo
ur
ob
serv
atio
n w
ith
an e
xp
lan
atio
n.
iii.
Wh
at h
app
ens
to t
he
ener
gy
of
the
elec
tro
ns
in t
he
ou
ter
mo
st
shel
l?
16
. L
oo
k a
t th
e P
ES
fo
r th
e el
emen
ts i
n t
he
thir
d p
erio
d (
sod
ium
– a
rgo
n)
and
des
crib
e y
ou
r ob
serv
atio
ns.
An
y s
urp
rise
s? E
xp
lain
.
A n
ota
tio
n h
as b
een
ag
reed
up
on
fo
r w
riti
ng
an
ele
ctro
n c
on
fig
ura
tio
n t
o i
den
tify
th
e
loca
tio
n o
f th
e sh
ell
and
sub
shel
l o
f ea
ch e
lect
ron
in
an
ato
m.
Sh
ells
are
lab
eled
wit
h a
nu
mb
er;
1,
2,
3,
etc.
an
d s
ub
shel
l ar
e la
bel
ed w
ith
let
ters
; s,
p, d
, an
d f
. E
ver
y s
hel
l
con
tain
s an
s s
ub
shel
l.
17
. W
rite
th
e co
mp
lete
ele
ctro
n c
on
fig
ura
tio
n f
or
the
firs
t te
n e
lem
ents
in
th
e p
erio
dic
tab
le?
Lo
ok
at
the
PE
S f
or
po
tass
ium
, ca
lciu
m a
nd
sca
nd
ium
.
18
. E
xp
lain
wh
at h
app
ens
in t
he
PE
S f
or
scan
diu
m t
hat
has
no
t o
ccu
rred
in
an
y
elem
ent
pri
or.
19
. If
on
e el
ectr
on
is
rem
ov
ed f
rom
sca
nd
ium
, w
hic
h e
lect
ron
(id
enti
fy t
he
shel
l an
d
sub
shel
l) r
equ
ires
th
e le
ast
amo
un
t o
f en
erg
y t
o r
emo
ve?
Nam
e:_
__
__
__
__
__
__
__
__
__
__
__
__
__
__
__
__
_D
ate:
__
__
__
__
__
__
__
__
__
__
_P
erio
d:_
__
__
Pag
e 1
of
4
© 2
004
Hig
h S
choo
l T
echn
olo
gy I
nit
iati
ve
(HS
TI)
Ed
uca
tion
al M
ater
ials
: T
he
AT
OM
: S
tru
ctu
re
Bo
hr M
od
el
Worksheet
Dir
ecti
on
s
Dra
w t
he
Bo
hr
Mo
del
s sh
ow
ing
all
th
e el
ectr
on
s in
eac
h e
ner
gy
lev
el.
1.
M
agn
esiu
m c
om
po
un
ds
are
use
d i
n t
he
pro
duct
ion o
f ura
niu
m f
or
nucl
ear
reac
tors
. D
raw
th
e B
oh
r m
od
el f
or
mag
nes
ium
.
Nie
ls B
oh
r
2.
So
diu
m i
s fo
un
d i
n s
alts
th
at c
an b
e u
sed
to
see
d c
lou
ds
to i
ncr
ease
rai
nfa
ll. D
raw
the
Bohr
mo
del
fo
r so
diu
m.
Nam
e:_
__
__
__
__
__
__
__
__
__
__
__
__
__
__
__
__
_D
ate:
__
__
__
__
__
__
__
__
__
__
_P
erio
d:_
__
__
Pag
e 2
of
4
© 2
004
Hig
h S
choo
l T
echn
olo
gy I
nit
iati
ve
(HS
TI)
Ed
uca
tion
al M
ater
ials
: T
he
AT
OM
: S
tru
ctu
re
3.
Neo
n i
s o
ften
fo
un
d i
n l
aser
s.
Dra
w t
he
Bo
hr
mo
del
fo
r n
eon
.
4.
Arg
on
gas
can
be
fou
nd
in
Gei
ger
co
un
ters
wh
ich
are
use
d t
o d
etec
t ra
dia
tion. D
raw
the
Bohr
mo
del
fo
r ar
go
n.
Nam
e:_
__
__
__
__
__
__
__
__
__
__
__
__
__
__
__
__
_D
ate:
__
__
__
__
__
__
__
__
__
__
_P
erio
d:_
__
__
Pag
e 3
of
4
© 2
004
Hig
h S
choo
l T
echn
olo
gy I
nit
iati
ve
(HS
TI)
Ed
uca
tion
al M
ater
ials
: T
he
AT
OM
: S
tru
ctu
re
5.
Alu
min
um
all
oy
s ar
e u
sed
in
air
pla
ne
con
stru
ctio
n d
ue
to t
hei
r lo
w d
ensi
ty. D
raw
th
e B
oh
r
mo
del
fo
r al
um
inu
m.
6.
Ox
yg
en i
s o
ften
ad
ded
to
ro
cket
fu
el a
s an
ox
idiz
er.
Dra
w t
he
Bo
hr
mo
del
fo
r o
xy
gen
.
Nam
e:_
__
__
__
__
__
__
__
__
__
__
__
__
__
__
__
__
_D
ate:
__
__
__
__
__
__
__
__
__
__
_P
erio
d:_
__
__
Pag
e 4
of
4
© 2
004
Hig
h S
choo
l T
echn
olo
gy I
nit
iati
ve
(HS
TI)
Ed
uca
tion
al M
ater
ials
: T
he
AT
OM
: S
tru
ctu
re
7. L
ith
ium
can
be
fou
nd
in
Mo
un
t P
alo
mar
’s 2
00
-in
ch t
eles
cop
ic m
irro
r. D
raw
th
e B
oh
r m
od
el
for
lith
ium
.
8.
Su
lfu
r d
iox
ide
is o
ften
use
d a
t w
ater
tre
atm
ent
faci
liti
es t
o d
ech
lori
nat
e w
ater
. D
raw
th
e B
oh
r
mo
del
fo
r su
lfu
r.
Page 1 of 8
Electron Configurations Worksheet
Write the complete ground state electron configurations and orbital notations for the following:
# of e Element (atom) e- configuration Orbital Notations/ diagrams 1) _____ lithium ___________________________ _________________________________ 2) _____ oxygen ___________________________ _________________________________ 3) _____ calcium ___________________________ _________________________________ 4) _____ nitrogen ___________________________ _________________________________ 5) _____ potassium ___________________________ _________________________________ 6) _____ chlorine ___________________________ _________________________________ 7) _____ hydrogen ___________________________ _________________________________ 8) _____ copper ___________________________ _________________________________ 9) _____ neon ___________________________ _________________________________ 10) _____ phosphorous ___________________________ _________________________________ Write the abbreviated ground state electron configurations, noble gas configuration, for the following: # of electrons Element Electron Configuration 11) ______ helium ________________________________________ 12) ______ nitrogen ________________________________________ 13) ______ chlorine ________________________________________ 14) ______ iron ________________________________________ 15) ______ zinc ________________________________________ 16) ______ barium ________________________________________ 17) ______ bromine ________________________________________ 18) ______ magnesium _______________________________________ 19) ______ fluorine __________________________________________ 20) ______ aluminum _______________________________________
Page 2 of 8
Electron Configuration Elements (atoms) and Ions Write the electron configuration and orbital notations for the following Atoms and ions: Element / Ions
Atomic number
# of e- Electron Configuration
F
F1-
O
O-2
Na
Na1+
Ca
Ca+2
Page 3 of 8
Al3+
Al
N
N3-
S2-
Cl1-
K1+
S
Br1-
Mg2+
Page 4 of 8
Electron Configuration Practice
Directions: Write and draw the electron configurations of each of the following atoms. Example: Co : 27 e- 1s2 2s2 2p6 3s2 3p6 4s2 3d7
1. Scandium: 2. Gallium: 3. Silver: 4. Argon: 5. Nitrogen: 6. Lithium: 7. Sulfur:
Co 1s 2s 2p 2p 2p 2p 3s 3p 3p 3p
3d 3d 3d 3d 3d 4s
Page 5 of 8
Electron Position and Configuration
Position: Draw the Electron Position of each of the following atoms. Example:
He:
1. Li 2. C
3. O 4. Ar
Directions: Draw the electron configurations of each of the following atoms. Example:
1. Chlorine: 2. Nitrogen: 3. Aluminum: 4. Oxygen:
5. Sodium: 6. Potassium: 7. Sulfur: 8. Calcium
F 1s 2s 2p 2p 2p 2p
Page 6 of 8
Electron Configuration Practice
In the space below, write the expanded electron configurations (ex. = 1s22s1) of the following elements:
1) Sodium ________________________________________________
2) potassium ________________________________________________
3) chlorine ________________________________________________
4) bromine ________________________________________________
5) oxygen ________________________________________________
In the space below, write the abbreviated electron configurations (ex. Li= [He]2s1) of the following elements:
6) manganese ________________________________________________
7) silver ________________________________________________
8) nitrogen ________________________________________________
9) sulfur ________________________________________________
10) argon ________________________________________________ In the space below, write the orbital notation (arrows) of the following elements:
11) manganese _______________________________________________
12) silver ________________________________________________
13) nitrogen ________________________________________________
14) sulfur ________________________________________________
15) argon ________________________________________________
Determine what elements are denoted by the following electron configurations:
16) 1s22s22p63s23p4 ____________________
17) 1s22s22p63s23p64s23d104p65s1 ____________________
18) [Kr] 5s24d105p3 ____________________
19) [Xe] 6s24f145d6 ____________________
20) [Rn] 7s25f11 ____________________ Determine which of the following electron configurations are not valid:
21) 1s22s22p63s23p64s24d104p5 __________________ 22) 1s22s22p63s33d5 ____________________
23) [Ra] 7s25f8 ____________________ 24) [Kr] 5s24d105p5 ____________________ 25) [Xe] ____________________
Page 7 of 8
Name______________________
Period___________________
Electrons, Valence, and Lewis Dot Structures Chem 544/545 Dr. Brielmann
1. How many electrons are present in:
Helium (He)_____ Carbon (C)_____ Neon (Ne)_____ Sodium (Na)_____ Zinc (Zn)____
2. How many valence electrons are present in:
Helium (He)_____ Carbon (C)_____ Neon (Ne)_____ Sodium (Na)_____
Potassium (K)_____ Fluorine (F)_____ Chlorine _____ Bromine_____
3. Draw Lewis Dot Structures for the following elements:
Helium (He) Carbon (C) Neon (Ne) Sodium (Na)
Ne
4. Correct the following Lewis Dot Structures:
Oxygen Nitrogen Beryllium Fluorine
O N Be F
5. Fill in the following table:
Carbon Carbon anion Carbon cation
number of electrons:
number of valence electrons
Lewis structure
C C- +
S-C-5-3_Periodic Trends Worksheet and KEY
10. For each of the following, circle or highlight the correct element that best matches the statement on the right.
Li Si S metal
N P As smallest ionization energy
K Ca Sc largest atomic mass
S Cl Ar member of the halogen family
Al Si P greatest electron affinity
Ga Al Si largest atomic radius
V Nb Ta largest atomic number
Te I Xe member of noble gases
Si Ge Sn 4 energy levels
Li Be B member of alkali metals
As Se Br 6 valence electrons
H Li Na nonmetal
Hg Tl Pb member of transition metals
Na Mg Al electron distribution ending in s2p1
Pb Bi Po metalloid
B C N gas at room temperature
Ca Sc Ti electron distribution ending in s2d2
Source: http://www.gpb.org/files/pdfs/gpbclassroom/chemistry/periodicTableTrendsWkst.pdf
Unit3NoteQuizQuestions
Unit 3.2: Electron Configuration
1. a
2. a
3. z
4.
5. a
6. a
7. A
8. A
9. A
10.
Unit 3.3: Periodic Trends
1. a
2.
3. A
4. a
5. a
6. a
7. a
8. a
9. a
10.