CHM 1
01Bas
i
cPr
i
nci
pl
esofI
nor
gani
cChemi
s
t
r
y
Theper
i
odi
ccl
as
s
i
f
i
cat
i
onoft
heel
ement
s
Out
l
i
ne
1
. Theper
i
odi
ccl
as
s
i
f
i
cat
i
onoft
heel
ement
s
.
1
.Thi
shi
ghl
i
ght
st
her
el
at
i
ons
hi
pbet
weenel
ect
r
oni
cconf
i
gur
at
i
onandt
heper
i
odi
c
cl
as
s
i
f
i
cat
i
onofel
ement
s
2.Showst
hear
r
angementofper
i
odi
candgr
oupsandt
hehi
s
t
or
i
caldevel
opmentoft
he
per
i
odi
ct
abl
e.
3.I
l
l
us
t
r
at
est
hemaj
orbl
ocks(
s
,p,d,f
)i
nt
heper
i
odi
ct
abl
eandbr
i
efont
hedi
f
f
er
ences
ands
i
mi
l
ar
i
t
i
es
4.Per
i
odi
cpr
oper
t
i
esofel
ement
s
:
(
i
)At
omi
cRadi
usand(
i
i
)i
oni
zat
i
onpot
ent
i
al
(
i
i
)El
ect
r
onaf
f
i
ni
t
y(
i
v)El
ect
r
onegat
i
vi
t
y
5.Gi
veabr
i
efont
heexi
s
t
enceofvar
i
ousoxi
dat
i
ons
t
at
es
6.Sol
veexampl
esandcont
i
nuousas
s
es
s
ment
1
CHM 1
01Bas
i
cPr
i
nci
pl
esofI
nor
gani
cChemi
s
t
r
y
Theper
i
odi
ccl
as
s
i
f
i
cat
i
onoft
heel
ement
s
THEPERI
ODI
CCLASSI
FI
CATI
ONOFELEMENTS
1
2
3
4
5
6
7
Fi
gur
e1
:Per
i
odi
cTabl
e
Themoder
nper
i
odi
ct
abl
epl
acesel
ement
si
nt
hes
,p,d-and f
bl
ocksand i
n
gr
oups1
–1
8oft
hePer
i
odi
cTabl
e(
Fi
gur
e1
)
.Per
i
odi
ci
t
yi
sacons
equenceoft
he
var
i
at
i
oni
ngr
ounds
t
at
eel
ect
r
oni
cconf
i
gur
at
i
ons(
El
ect
r
oni
cconf
i
gur
at
i
onswi
l
l
be t
r
eat
ed by a col
ect
ur
eri
nt
hi
scour
s
e)
,and many phys
i
caland chemi
cal
pr
oper
t
i
esf
ol
l
ow per
i
odi
ct
r
ends
.
(
1
) Acr
os
st
het
abl
e,wehavet
heper
i
odscor
r
es
pondi
ngt
ot
hen(
pr
i
nci
pal
quant
um number
)val
ues
,whi
l
edownt
het
abl
ewehavet
hegr
oupsofel
ement
s
wi
t
hs
i
mi
l
arpr
oper
t
i
es
,i
.
e.
,f
r
om Gr
oup1
→2and1
3→1
7,andt
henGr
oup1
8.
2
CHM 1
01Bas
i
cPr
i
nci
pl
esofI
nor
gani
cChemi
s
t
r
y
Theper
i
odi
ccl
as
s
i
f
i
cat
i
onoft
heel
ement
s
Anss
ubs
hel
li
sf
i
l
l
edwhenwecr
os
sGr
oups1AND2ns
1andns
2.
(
2)
np6)
.
A ps
ubs
hel
li
sf
i
l
l
edaswegot
hr
oughgr
oups1
3→1
7andGr
oup1
8(
np1–
A ds
ubs
hel
li
sf
i
l
l
edwhenwepas
st
hr
oughar
ow oft
r
ans
i
t
i
onel
ement
si
.
e.
,
(
n-1
)
d1–d10)
,Gr
oups3→1
2.
Anfs
ubs
hel
li
sf
i
l
l
edwhenwepas
sacr
os
sar
ow ofi
nnert
r
ans
i
t
i
onel
ement
s(
(
n1
1
4
2)
f–f )
.
Gr
oups
Fi
l
l
i
ng
or
bi
t
al
s
1
→2A,1
3→1
8mai
n s1-2
gr
oupofGr
oup
(
s
-bl
ock)
r
epr
es
ent
at
i
ve
el
ement
si
.
e.
,sand p1-6
p-bl
ockel
ement
s
.
Pr
i
nci
pl
eQuant
um
no.
oft
hef
i
l
l
i
ngor
bi
t
al
s
n
Per
i
odno.of
f
i
l
l
i
ng
or
bi
t
al
s
n
n
n
Tr
ans
i
t
i
on
d1-10
n1
el
ement
s(
d-bl
ock
(
d-bl
ock)
el
ement
s
)
I
nnerTr
ans
i
t
i
on
el
ement
s
(
Lant
hani
desand
Act
i
ni
des
)
1
1
4
f
n2
n
n
THEPERI
ODI
CPROPERTI
ESOFELEMENTS
Res
t
at
ementoft
hemoder
nper
i
odi
cl
aw:Thepr
oper
t
i
esofel
ement
sar
eaper
i
odi
c
f
unct
i
on oft
hei
rel
ect
r
oni
c conf
i
gur
at
i
ons
.Thati
sal
lphys
i
caland chemi
cal
behavi
oroft
heel
ement
si
sbas
edul
t
i
mat
el
yont
heel
ect
r
onconf
i
gur
at
i
onsoft
hei
r
at
oms
.
Thepr
oper
t
i
esar
easf
ol
l
ows
:
At
omi
cr
adi
us(
s
i
ze)
1
. Theat
omi
cr
adi
usofanat
om coul
d bet
akenashal
ft
hedi
s
t
ancebet
ween
3
CHM 1
01Bas
i
cPr
i
nci
pl
esofI
nor
gani
cChemi
s
t
r
y
Theper
i
odi
ccl
as
s
i
f
i
cat
i
onoft
heel
ement
s
nei
ghbour
i
ngat
omswhent
heel
ementi
si
ni
t
smos
tdens
ef
or
m(
us
ual
l
ys
ol
i
d
s
t
at
e)
.
2.Downagr
oupi
nt
heper
i
odi
ct
abl
e,t
heat
omi
cr
adi
usi
ncr
eas
esbecaus
eoft
he
i
ncr
eas
ei
nnval
ues
,aswel
last
hes
cr
eeni
ngoft
heel
ect
r
onsi
nt
heout
ers
hel
l
byt
hos
ei
nt
hei
nners
hel
l
s
.
3.Acr
os
saper
i
odt
heat
omi
cr
adi
usdecr
eas
esbecaus
eoft
hei
ncr
eas
i
ngnucl
ear
char
gewhi
l
et
heel
ect
r
onsaddont
ot
hes
ameout
er
mos
ts
hel
l
.
Aswepas
st
hr
ought
her
ow oft
r
ans
i
t
i
onandi
nnert
r
ans
i
t
i
onel
ement
s
,t
hi
s
decr
eas
ei
sl
es
st
hant
hatf
ort
hesandpbl
ockel
ement
s(
mai
ngr
oupor
r
epr
es
ent
at
i
veel
ement
s
)becaus
et
heel
ect
r
onsnow addt
ot
hei
nners
hel
l(
n–1
)or
(
n–2)
.
 Aswemovef
r
om l
ef
tt
or
i
ght
,s
i
zes
hr
i
nkst
hr
ought
hef
i
r
s
tt
woort
hr
ee
t
r
ans
i
t
i
onel
ement
sbecaus
eoft
hei
ncr
eas
i
ngnucl
earchar
ge.But
,f
r
om t
hen
on,t
hes
i
zer
emai
nsr
el
at
i
vel
y cons
t
antbecaus
es
hi
el
di
ng by t
hei
nnerd
el
ect
r
onscount
er
act
st
heus
uali
ncr
eas
ei
nZef
f(
ef
f
ect
i
venucl
earchar
ge)
.
Fori
ns
t
ance,vanadi
um (
V;Z =23)
,t
het
hi
r
dPer
i
od4t
r
ans
i
t
i
onmet
al
,has
t
hes
ameat
omi
cr
adi
usaszi
nc(
Zn;Z = 30)
,t
hel
as
tPer
i
od 4 t
r
ans
i
t
i
on
met
al
.Thi
spat
t
er
nofat
omi
cs
i
zes
hr
i
nki
ngal
s
oappear
si
nPer
i
ods5and6
i
nt
hedbl
ockt
r
ans
i
t
i
ons
er
i
esandi
nbot
hs
er
i
esofi
nnert
r
ans
i
t
i
onel
ement
s
.
Thel
ackofaver
t
i
cals
i
zei
ncr
eas
ef
r
om t
hePer
i
od5t
o6t
r
ans
i
t
i
onmet
ali
s
es
peci
al
l
y obvi
ous
.Thi
ss
hi
el
di
ng by d el
ect
r
ons caus
es a maj
ors
i
ze
decr
eas
ef
r
om Gr
oup 2 t
oGr
oup 1
3,t
het
womai
ngr
oupst
hatf
l
ankt
he
t
r
ans
i
t
i
ons
er
i
es
.Thes
i
zedecr
eas
ei
nPer
i
ods4,5,and6(
wi
t
hat
r
ans
i
t
i
on
s
er
i
es
)i
smuchgr
eat
ert
hani
nPer
i
od3(
wi
t
houtat
r
ans
i
t
i
ons
er
i
es
)
.Becaus
e
el
ect
r
onsi
nt
henpor
bi
t
al
spenet
r
at
emor
et
hant
hos
ei
nt
he(
n1
)
dor
bi
t
al
s
,
t
hef
i
r
s
tnpel
ect
r
on[
Gr
oup1
3]“
f
eel
s
”aZef
ft
hathasbeeni
ncr
eas
edbyt
he
pr
ot
onsaddedt
oal
lt
hei
nt
er
veni
ngt
r
ans
i
t
i
onel
ement
s
.Thegr
eat
es
tchange
i
ns
i
zeoccur
si
nPer
i
od4,i
nwhi
chcal
ci
um (
Ca;Z=20)i
snear
l
y50%l
ar
ger
t
hangal
l
i
um (
Ga;Z=31
)
.I
nf
act
,s
hi
el
di
ngbyt
hedor
bi
t
al
si
nt
het
r
ans
i
t
i
on
s
er
i
escaus
ess
uchamaj
ors
i
zecont
r
act
i
ont
hatgal
l
i
um i
ss
l
i
ght
l
ys
mal
l
er
4
CHM 1
01Bas
i
cPr
i
nci
pl
esofI
nor
gani
cChemi
s
t
r
y
Theper
i
odi
ccl
as
s
i
f
i
cat
i
onoft
heel
ement
s
t
hanal
umi
num (
Al
;Z=1
3)
,event
houghGai
sbel
ow Ali
nt
hes
amegr
oup!
4. Thepos
i
t
i
vei
onofanel
ementhasas
mal
l
err
adi
ust
hant
heneut
r
alat
om whi
l
e
t
henegat
i
vei
onhasal
ar
gerr
adi
us
.
5. I
s
oel
ect
r
oni
c(
s
amenumberofel
ect
r
ons
)i
onswi
l
ldi
f
f
eri
nat
omi
cs
i
ze
dependi
ngont
hei
rnucl
earchar
ges
.Themor
et
henucl
earchar
ge,t
hel
es
st
hes
i
ze
duet
oi
ncr
eas
edf
or
ceofat
t
r
act
i
on.
e.
g.02-˃F-˃Ne˃Na+ ˃Mg2+
+8
2
2
1
s
2s
2p6
+9 +1
0 +1
1 +1
2
6. Di
s
cr
epanci
esar
i
s
ei
ns
i
zesofadj
oi
ni
ngel
ement
sduet
oanyoft
hef
ol
l
owi
ng
r
eas
ons
:
(
a.
) Or
bi
t
alpenet
r
at
i
on
(
b.
) Shi
el
di
ngofi
ons
.
I
oni
zat
i
onEner
gy(
I
.
E)
Thei
oni
zat
i
onener
gy(
I
E)i
st
heener
gy(
i
nkJ
)r
equi
r
edf
ort
hecompl
et
er
emoval
of1molofel
ect
r
onsf
r
om 1molofgas
eousat
omsori
ons
.Pul
l
i
nganel
ect
r
on
awayf
r
om anucl
eusr
equi
r
esener
gyt
oover
comet
heat
t
r
act
i
on.Becaus
eener
gy
f
l
owsi
nt
ot
hes
ys
t
em,t
hei
oni
zat
i
onener
gy i
sal
wayspos
i
t
i
ve(
l
i
keΔH ofan
endot
her
mi
cr
eact
i
on)
.
5
CHM 1
01Bas
i
cPr
i
nci
pl
esofI
nor
gani
cChemi
s
t
r
y
Theper
i
odi
ccl
as
s
i
f
i
cat
i
onoft
heel
ement
s
Fi
gur
e2:Thevar
i
at
i
onofval
uesoft
hef
i
r
s
ti
oni
zat
i
onener
gy(
I
E1)wi
t
hi
ncr
eas
i
ngat
omi
cnumber
.
(
1
)Thei
oni
zat
i
onener
gyoft
heH at
om i
st
heener
gydi
f
f
er
encebet
weenn=1and
n=∞,t
hepoi
ntatwhi
cht
heel
ect
r
oni
scompl
et
el
yr
emoved.Manyel
ect
r
on
at
omscanl
os
emor
et
hanoneel
ect
r
on.Thef
i
r
s
ti
oni
zat
i
onener
gy(
I
E1)r
emoves
anout
er
mos
tel
ect
r
on(
hi
ghes
tener
gys
ubl
evel
)f
r
om t
hegas
eousat
om:
+
+
At
om(
g)→i
on(
g)+e ΔE =I
E1>0
e.
g.
Na(g)→Na+ (g)+e-
s
t
1
i
oni
zat
i
onener
gy
Thes
econdi
oni
zat
i
onener
gy(
I
E2)r
emovesas
econdel
ect
r
on.Thi
sel
ect
r
oni
s
pul
l
edawayf
r
om apos
i
t
i
vel
ychar
gedi
on,s
oI
E2 i
sal
waysl
ar
gert
hanI
E1:
I
on+(
g)i
on2+(
g)+e-ΔE =I
E2 (
al
ways>I
E1
)
e.
g.Na(g)→Na++(g)+e-
2nd i
oni
zat
i
onener
gy
s
t
Thet
r
endi
ni
oni
zat
i
onener
gyi
s1
<2nd <3rd <4th.
.
.
Thef
i
r
s
ti
oni
zat
i
onener
gy i
sa key f
act
ori
nanel
ement
’
schemi
calr
eact
i
vi
t
y
becaus
e,asyou’
l
ls
ee,at
omswi
t
hal
ow I
E1t
endt
of
or
m cat
i
onsdur
i
ngr
eact
i
ons
,
wher
east
hos
ewi
t
hahi
ghI
E1(
exceptt
henobl
egas
es
)of
t
enf
or
m ani
ons
.
Fi
gur
e2s
howst
het
r
endi
nt
hef
i
r
s
ti
oni
zat
i
on(
I
E1)acr
os
st
heper
i
odi
ct
abl
ef
r
om
6
CHM 1
01Bas
i
cPr
i
nci
pl
esofI
nor
gani
cChemi
s
t
r
y
Theper
i
odi
ccl
as
s
i
f
i
cat
i
onoft
heel
ement
s
l
ef
tt
or
i
ght
.Theval
ueofI
E1f
orhel
i
um (
t
henobl
egaswhi
chpr
ecedesl
i
t
hi
um i
n
t
heper
i
odi
ct
abl
e)
.Thr
eef
eat
ur
esi
nt
hegr
aphcanbes
een:(
i
)t
her
ei
sas
har
p
decr
eas
ei
nt
heval
ueofI
E1i
ngoi
ngf
r
om Het
oLi(
i
i
)Ther
ei
sagener
ali
ncr
eas
e
i
nt
heval
uesofI
E1 i
ncr
os
s
i
ngt
heper
i
od.(
i
i
i
)Ther
ei
sagener
ali
ncr
eas
ei
nt
he
val
uesofI
E1i
ncr
os
s
i
ngt
heper
i
od
Thes
eobs
er
vat
i
onscanber
at
i
onal
i
zedi
nt
er
msoft
hear
r
angementoft
heval
ence
el
ect
r
ons(
Readupel
ect
r
onconf
i
gur
at
i
onofel
ement
s
)
i
. Hel
i
um t
ol
i
t
hi
um:Thef
i
r
s
ti
oni
zat
i
onener
gyf
orHer
ef
er
st
ot
hepr
oces
si
n
equat
i
onbel
ow.Anel
ect
r
oni
sr
emovedf
r
om af
i
l
l
ed1
ss
hel
l
,butt
her
ei
s
2
s
omes
peci
als
t
abi
l
i
t
yas
s
oci
at
ed wi
t
ht
he1
s conf
i
gur
at
i
on.Removi
ngan
el
ect
r
onf
r
om t
hef
i
l
l
ed 1
sor
bi
t
alr
equi
r
esa r
el
at
i
vel
yl
ar
geamountof
ener
gy.
He(
g)→ He+(
g)+e
2
1
1
s
1
s
2
The gr
ound s
t
at
e el
ect
r
oni
c conf
i
gur
at
i
on of Lii
s1
s
2s
1and t
he f
i
r
s
t
i
oni
zat
i
onener
gyi
st
heener
gyr
equi
r
edt
or
emovet
he2sel
ect
r
on.Thi
si
st
he
onl
y el
ect
r
on i
nt
he val
ence s
hel
land r
emovi
ng i
ti
sa r
el
at
i
vel
y eas
y
pr
oces
s
.
i
i
. Li
t
hi
um t
o neon:I
ngoi
ng f
r
om Lit
oNe,t
wos
i
gni
f
i
cantchangesoccur
:
f
i
r
s
t
l
y,t
heval
ences
hel
li
sf
i
l
l
edwi
t
hel
ect
r
onsi
nas
t
epwi
s
emannerand
s
econdl
yt
heef
f
ect
i
venucl
earchar
gei
ncr
eas
esand t
heat
omi
c or
bi
t
al
s
cont
r
act
.I
tf
ol
l
owst
hati
tbecomesi
ncr
eas
i
ngl
ydi
f
f
i
cul
t(
mor
eener
gyi
s
needed)t
or
emoveanel
ect
r
onf
r
om t
heval
ences
hel
longoi
ngf
r
om anat
om
wi
t
ht
he[
He]
2s
1gr
ounds
t
at
econf
i
gur
at
i
on(
Li
)t
oonewi
t
ht
he[
He]
2s
22p6
conf
i
gur
at
i
on(
Ne)
.
i
i
i
.
Acr
os
sa per
i
od,i
oni
zat
i
onener
gy i
ncr
eas
esbecaus
et
henucl
earchar
ge
i
ncr
eas
eswhi
l
eat
omi
cr
adi
usdecr
eas
es
.Ther
ef
or
e,el
ect
r
onsar
ehel
dmor
e
nd
f
i
r
ml
yandcannotbeeas
i
l
yr
emoved.I
nt
he2 per
i
od,t
hi
st
r
endi
sr
ever
s
ed
i
npas
s
i
ngf
r
om Be→BandN→0.Si
mi
l
art
r
endsoccurf
ort
hecor
r
es
pondi
ng
el
ementi
nt
heot
herper
i
ods
.Ther
eas
oni
sduet
oei
t
herhal
f
f
i
l
l
eds
ubs
hel
l
s
orcompl
et
el
yf
i
l
l
eds
ubs
hel
l
s
:
2
Be 1
s
2
2s
B
2
1
s
2
2s
2p1
N
2
1
s
2
2s
2p3
0
2
1
s
2
2s
2p4
4
5
7
8
(
cl
os
edor
bi
t
al
s
)
(
hal
ff
i
l
l
ed)
7
CHM 1
01Bas
i
cPr
i
nci
pl
esofI
nor
gani
cChemi
s
t
r
y
(
2)
Theper
i
odi
ccl
as
s
i
f
i
cat
i
onoft
heel
ement
s
The i
oni
zat
i
on ener
gi
es of t
he t
r
ans
i
t
i
on el
ement
s ar
e aboutt
he s
ame
becaus
et
hes
cr
eeni
ngef
f
ectcaus
edbyaddi
ngel
ect
r
onst
ot
hei
nners
hel
l
r
oughl
ybal
ancest
hei
ncr
eas
i
ngnucl
earchar
ge.
Gener
al
l
y,
(
3)
Downagr
oup,i
oni
zat
i
onener
gydecr
eas
esbecaus
eoft
hel
ar
gei
ncr
eas
ei
n
at
omi
cr
adi
us
,andt
henucl
eusi
sl
es
sef
f
ect
i
vei
nat
t
r
act
i
ngt
heout
er
mos
t
el
ect
r
on.
(
4)
The l
es
st
he i
oni
zat
i
on ener
gy,t
he mor
et
he met
al
l
i
c char
act
eroft
he
el
ement
.Thi
si
swhyt
hemet
al
l
i
cchar
act
eri
ncr
eas
esdownt
hegr
oupwhi
l
e
acr
os
saper
i
odt
hemet
al
l
i
cchar
act
erdecr
eas
es
.
(
5) Ther
ar
egas
esi
ngr
oup1
8havedupl
etoroct
etconf
i
gur
at
i
onswhi
char
e
ver
ys
t
abl
e.Ther
ef
or
e,t
hei
ri
oni
zat
i
onener
gi
esar
ever
yhi
ghandt
hey
har
dl
yf
or
m cat
i
ons
.
El
ect
r
onAf
f
i
ni
t
y(
E.
A)
Theel
ect
r
onaf
f
i
ni
t
y(
EA)i
st
heener
gychange(
i
nkJ
)accompanyi
ngt
headdi
t
i
on
of1molofel
ect
r
onst
o1molofgas
eousat
omsori
ons
.Aswi
t
hi
oni
zat
i
onener
gy,
t
her
ei
saf
i
r
s
tel
ect
r
onaf
f
i
ni
t
y,as
econd,ands
of
or
t
h.Thef
i
r
s
tel
ect
r
onaf
f
i
ni
t
y
(
EA1)r
ef
er
st
ot
hef
or
mat
i
onof1molofmonoval
ent(
1
)gas
eousani
ons
:
At
om(
g)+e- → i
on-(
g)ΔE =EA1
I
nmos
tcas
es
,ener
gyi
sr
el
eas
edwhent
hef
i
r
s
tel
ect
r
oni
sadded becaus
ei
ti
s
at
t
r
act
edt
ot
heat
om’
snucl
earchar
ge.Thus
,EA1 i
sus
ual
l
ynegat
i
ve(
j
us
tasΔH
f
or an exot
her
mi
cr
eact
i
on i
s negat
i
ve)
.
* The s
econd el
ect
r
on af
f
i
ni
t
y(
EA2)
,
however
,i
s al
ways pos
i
t
i
ve becaus
e ener
gy mus
tbe abs
or
bed t
o over
come
el
ect
r
os
t
at
i
cr
epul
s
i
onsandaddanot
herel
ect
r
ont
oanegat
i
vei
on.
8
CHM 1
01Bas
i
cPr
i
nci
pl
esofI
nor
gani
cChemi
s
t
r
y
Theper
i
odi
ccl
as
s
i
f
i
cat
i
onoft
heel
ement
s
s
t
e.g.Cl
l
exot
her
mi
c)1
el
ect
r
onaf
f
i
ni
t
y
(
g)+e →C
(
g)(
2Cl
-→Cl
endot
her
mi
c)2nd E.
A
(
g)+e
(
g)(
*
El
ect
r
onAf
f
i
ni
t
yi
sameas
ur
eofabi
l
i
t
yt
of
or
m ani
ons
.
Fact
or
sot
hert
hanZef
fandat
omi
cs
i
zeaf
f
ectel
ect
r
onaf
f
i
ni
t
i
es
,s
ot
r
endsar
enot
asr
egul
arast
hos
ef
ort
heat
omi
cs
i
zeand i
oni
zat
i
onener
gy.Fori
ns
t
ance,we
mi
ghtexpectel
ect
r
on af
f
i
ni
t
i
est
o decr
eas
es
moot
hl
y down a gr
oup (
s
mal
l
er
negat
i
venumber
)becaus
et
henucl
eusi
sf
ar
t
heraway f
r
om anel
ect
r
onbei
ng
added.Onl
y Gr
oup 1exhi
bi
t
st
hi
sbehavi
or
.We mi
ghtal
s
o expecta r
egul
ar
i
ncr
eas
ei
nel
ect
r
onaf
f
i
ni
t
i
esacr
os
saper
i
od(
l
ar
gernegat
i
venumber
)becaus
e
s
i
zedecr
eas
esand t
hei
ncr
eas
i
ng Zef
fs
houl
d at
t
r
actt
heel
ect
r
onbei
ngadded
mor
es
t
r
ongl
y.An over
al
ll
ef
t
t
or
i
ghti
ncr
eas
ei
n magni
t
ude i
st
her
e,butwe
cer
t
ai
nl
y cannots
ay t
hati
ti
sa r
egul
ari
ncr
eas
e.Thes
eexcept
i
onsar
i
s
ef
r
om
changes i
ns
ubl
evel ener
gy and i
n el
ect
r
onel
ect
r
on r
epul
s
i
on.Des
pi
t
et
he
i
r
r
egul
ar
i
t
i
es
,t
hr
eekeypoi
nt
semer
gewhenweexami
net
her
el
at
i
veval
uesof
i
oni
zat
i
onener
gyandel
ect
r
onaf
f
i
ni
t
y:
1
.React
i
venonmet
al
s
.Theel
ement
si
nGr
oup1
6andes
peci
al
l
yt
hos
ei
nGr
oup1
7
(
hal
ogens
)havehi
ghi
oni
zat
i
onener
gi
esandhi
ghl
ynegat
i
ve(
exot
her
mi
c)el
ect
r
on
af
f
i
ni
t
i
es
.Thes
eel
ement
sl
os
eel
ect
r
onswi
t
hdi
f
f
i
cul
t
ybutat
t
r
actt
hem s
t
r
ongl
y.
Ther
ef
or
e,i
nt
hei
ri
oni
ccompounds
,t
heyf
or
m negat
i
vei
ons
.
2.React
i
vemet
al
s
.Theel
ement
si
nGr
oups1and2havel
ow i
oni
zat
i
onener
gi
es
ands
l
i
ght
l
ynegat
i
ve(
exot
her
mi
c)el
ect
r
onaf
f
i
ni
t
i
es
.I
nbot
hgr
oups
,t
heel
ement
s
l
os
eel
ect
r
onsr
eadi
l
ybutat
t
r
actt
hem onl
yweakl
y,i
fatal
l
.Ther
ef
or
e,i
nt
hei
r
i
oni
ccompounds
,t
heyf
or
m pos
i
t
i
vei
ons
.
3.Nobl
egas
es
.Theel
ement
si
nGr
oup1
8havever
yhi
ghi
oni
zat
i
onener
gi
es
and s
l
i
ght
l
ypos
i
t
i
ve(
endot
her
mi
c)el
ect
r
onaf
f
i
ni
t
i
es
.Ther
ef
or
e,t
hes
eel
ement
s
t
endnott
ol
os
eorgai
nel
ect
r
ons
.I
nf
act
,onl
yt
hel
ar
germember
soft
hegr
oup(
Kr
,
Xe,Rn)f
or
m anycompoundsatal
l
.
Wi
t
hmanyexcept
i
ons
,acr
os
saper
i
od,el
ect
r
onaf
f
i
ni
t
y“
i
ncr
eas
es
”becaus
e
oft
hedecr
eas
i
ngat
omi
cs
i
zeandt
henucl
euscanat
t
r
actt
hei
ncomi
ngel
ect
r
on
eas
i
l
y.Downagr
oupt
heel
ect
r
onaf
f
i
ni
t
ydecr
eas
esduet
oi
ncr
eas
i
ngat
omi
cs
i
ze.
However
,s
omei
r
r
egul
ar
i
t
i
esoccurduet
oi
nt
erel
ect
r
oni
cr
epul
s
i
on.
9
CHM 1
01Bas
i
cPr
i
nci
pl
esofI
nor
gani
cChemi
s
t
r
y
Theper
i
odi
ccl
as
s
i
f
i
cat
i
onoft
heel
ement
s
El
ect
onegat
i
vi
t
y
 Thi
si
st
her
el
at
i
veabi
l
i
t
yofabondedat
om t
oat
t
r
actt
hes
har
edel
ect
r
onsa
chemi
calbond. Thet
r
endi
nel
ect
r
onegat
i
vi
t
yi
nt
heper
i
odi
ct
abl
ei
st
he
s
ameast
hatofi
oni
zat
i
onener
gyandel
ect
r
onaf
f
i
ni
t
y.Thati
s
,i
ti
ncr
eas
es
acr
os
saper
i
odanddecr
eas
esdownagr
oup.
 ByPaul
i
ng s
t
andar
ds
,t
hemos
tel
ect
r
onegat
i
veel
ementi
sF as
s
i
gned an
ar
bi
t
r
ar
yval
ueof4.Ot
herel
ement
sar
eas
s
i
gnedval
uesi
ncompar
i
s
onwi
t
h
t
heFs
t
andar
d.
El
ement
s
El
ect
r
onegat
i
vi
t
y
F
O
N
C
H
B
Be
Li
Cl
S
P
Si
Ge
Al
4
3.
5
3
2.
5
2.
1
2.
0
1
.
5
1
.
0
3.
0
2.
5
2.
1
1
.
8
1
.
7
1
.
5
1
0
CHM 1
01Bas
i
cPr
i
nci
pl
esofI
nor
gani
cChemi
s
t
r
y
Theper
i
odi
ccl
as
s
i
f
i
cat
i
onoft
heel
ement
s
Mg
1
.
2
Na
0.
9
 Whent
hedi
f
f
er
encei
nel
ect
r
onegat
i
vi
t
ybet
ween2el
ement
si
nabond i
s
about0.
9,t
hebondi
s50% i
oni
cand50% coval
ent
.Above0.
9t
hebondi
s
pr
edomi
nant
l
yi
oni
cwhi
l
ebel
ow 0.
9i
ti
spr
edomi
nant
l
ycoval
ent
.
 El
ect
r
oegat
i
vi
t
y val
uescanbeus
ed t
ocal
cul
at
ebond ener
gi
esbet
ween
at
omsofel
ement
sus
i
ngt
hef
or
mul
a:
2
D(A-B)=½[
D(A-A)+D(B-B)]+23.
06(
XAXB)
Pr
ovi
dedXA andXB ar
el
ar
gel
ydi
f
f
er
ent
.
Wher
eD(A-B)=Si
ngl
ebondener
gybet
weenat
omsA&Bi
nkcal
/mol
e,(
AB)
.
D(A-A)=Si
ngl
ebondener
gybet
ween2at
omsofAi
nkcal
/mol
e(
AA)
.
D(B-B)=Si
ngl
ebondener
gybet
ween2at
omsofBi
nkcal
/mol
e,(
BB)
XA
=el
ect
r
onegat
i
vi
t
yval
ueofA
XB
=el
ect
r
onegat
i
vi
t
yval
ueofB
Somes
i
ngl
ebondener
gyval
uesi
nkcal
/mol
ear
e:
HH 1
04
CC 82
NN 32
OO 33
FF 37
PP 51
SS 49
Si
Si 50
Cl
Cl58
NaNa1
6
Li
Li 26
KK 1
2
HF 1
35
HN 84
HP 76
CCl 79
Si
Cl 90
GeCl80
CN 64
CS 75
NF 56
CF 1
02
CH 1
00
ELECETRONEGATI
VI
TYANDOXI
DATI
ONNUMBER
Onei
mpor
t
antus
eofel
ect
r
onegat
i
vi
t
yi
si
ndet
er
mi
ni
nganat
om’
soxi
dat
i
on
number(
ON)
.
1
.Themor
eel
ect
r
onegat
i
veat
om i
nabondi
sas
s
i
gnedal
lt
hes
har
edel
ect
r
ons
;t
he
l
es
sel
ect
r
onegat
i
veat
om i
sas
s
i
gnednone.
2.Eachat
om i
nabondi
sas
s
i
gnedal
lofi
t
suns
har
edel
ect
r
ons
.
1
1
CHM 1
01Bas
i
cPr
i
nci
pl
esofI
nor
gani
cChemi
s
t
r
y
Theper
i
odi
ccl
as
s
i
f
i
cat
i
onoft
heel
ement
s
3.Theoxi
dat
i
onnumberi
sgi
venby;
O.
N.=no.ofval
encee(
no.ofs
har
ede-+no.ofuns
har
ede-)
I
nHCl
,f
orexampl
e,Cli
smor
eel
ect
r
onegat
i
vet
hanH.I
thas7val
enceel
ect
r
ons
buti
sas
s
i
gned8(
2s
har
ed+6uns
har
ed)
,s
oi
t
soxi
dat
i
onnumberi
s
7-8=1
.TheHat
om has1val
enceel
ect
r
onandi
sas
s
i
gnednone,s
oi
t
soxi
dat
i
on
numberi
s1-0=+1
.
Al
s
o;
i
.Anel
ementwi
l
lr
eadi
l
yi
oni
zet
oas
s
umeanoxi
di
zeds
t
at
ei
nwhi
cht
he
conf
i
gur
at
i
oni
ss
t
abl
ei
.
ehal
f
f
i
l
l
edorcompl
et
el
yf
i
l
l
edor
bi
t
alconf
i
gur
at
i
one.
g.
+
+
2+
3+
2Na,Li.F,Mg ,Al andO .
Thi
si
st
r
uef
ort
hemai
ngr
oupel
ement
s
1
,2,1
3,1
4,1
5,1
6,1
7.
i
i
.f
ort
r
ans
i
t
i
onel
ement
st
heyhavevar
i
abl
eoxi
dat
i
ons
t
at
esbecaus
eoft
hei
r
i
ncompl
et
el
yf
i
l
l
eddor
bi
t
al
s
.Var
i
abl
esnumberofd,el
ect
r
oncanbel
os
tbutt
he
mos
ts
t
abl
eoxi
dat
i
ons
t
at
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