1. No category

WHYI}O CERTAIN
ELTIVIENTS
LINKUPTf,
FORMCOMPOUNIIS
20
".(i r, ti'r
ff\u
lt-Y
:nrortn
0u
a
t
AIM lwhv do certain elemenis
O
compounds?
folm
to
up
20 I tittt
electron sbells' you can
about
know
you
that
Now
atoms link up'
understand more about why
full'
outer shells that are not
Atoms that link up have
o' iotittg the outer-ring elecThe atoms link up by gaining
g
electrons is needed'
trons. A total of outer-iirrg
7 outer-ring'electrons
For example, an atom-with
with an atom with 1 outerwill form;;;;;"d
page123']
[see Figure A'
ring electrl;j;'l;;81'
electrons will link
An atom with 6 outer-ring
with- 2 outer-ring electrons'
up with
"olto* Figur e B' Page124' 1
[6 + 2 : a l .- lG
electrons tells us if an atom
The number of outer-ring
thon 4
Atom" o1 mttols hove f ewer more
-ti"g
is a metal or nonmetal'
Atoms of nonmetols hove
electrons i., tnJ ou't"t
r lng'
th o n 4 e l e ctro n sin the outer
lend" electr ons '
pounds' m etals ""lend"
Wh e n fo rming com
r -^-^-i\ nnrnnnund
compound has at least one
A
electrons'
"borrow"
Nonmetals
metal and one nonmetal'
M
E
T
A
I
l
I
I
i
ECTRONS
with anv other eiements'
Some atoms do not link uP '*-ittt another kind of
combine
And not every atom that con
atom'
*ill .o*bine with the other
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t
122
Study thr
about rwo compounds is given below'
DRAWTNGA InJormation4ud
then iook it the drawing of each compound
information
COMPOUND Trv to answer the questionsabout each compound'
,,
the compound sodium chlorici
i. sodium (Na) and chlorine (cl) link up to form
tNaCl). This is table salt.
CHLONINE(CI)
SODIUM [Na]
Atomic number = 11
Atomic weigbt = 23
Protons : 11
Neutrons = 12
Electrons = 11
K :2eL :8eM=1e-
Atomic number: 17
Atomic weight = 35
Protons = 17
Neutrons = 18
Electrons : 17
K =2eL = 8eM: 7e'
M= le
L=8cK=2c
1
I
1.
,
have?
a) How many outer-ring electrons does sodium
b)
Is the outer shell full?
c)
Is sodium a metal or a nonmetal?
have?
a) How many outer-ring electronsdoes chlorine
b)
Is this a full outershell?
c)
Is chlorine a metal or a nonmetal?
a)
sodium and chlorine have
Altogether, how many outer'ring electrons do
(Countthem.)
b)
Together, do they make a full shell?
12
4.
Which atom is the eiectron "lender"?
5.
How many elecbons are lent?
6.
Which atom borrows the eiectron?
a
How many electrons are borrowedl
8.
What is formed, a mixture or a compound?
9.
When sodium and chlorine link up, do their properties change?
II.
Calcium and orygen ioin to forrn the compound calcium oxide (CaO).
CALCIUM (Ca)
Atomic number = 20
Atomic weight: +0
Protons = 20
Neubons: 20
Electrons = 20
1 . a)
r24
K:ZeL :8eM = BeN=2e-
o
oxrGEN(o)
Atomic number = 8
Atomic rveight = t6
Protons : B
Neutrons: 8
Electrons = 8
How many outer-ring electronsdoes calcium have?
b)
Is the outer ring full?
c)
Is calcium a metal or nonmetal?
K = 2eL = 6e-
I
.j
>
-'
*
t
2. a) How many outer-ringelectronsdoesox-vgenhave?
b) ls this a iull shell?
c ) i s o x y g e na m e t a l o r a n o n m e t a l ?
L
3. a) Altogether,how many outer-ring electrons do calcium and orygen have?
**
(Countthem.)
.J
b) Together,do they make a full shell?
I
F
4. Which atom lends elecbons?
t-
:'
5. How many electrons are lent?
6.
Which atom borrows the electrons?
7. How manv electrons are bomowed?
8. What is formed, a mixture or a compound?
9. When calcium and ox1'genlink up, do their propertieschange?
1. .Vfetoishave fewer thon 4 electrons in the outer ring.
Remember:
2 . N o n m e t o J sh a v e m o r e t h o n J e l e c t r o n si n t h e o u t e r r i n g .
3. \letals lend electrons.
4. Nonmetals borrorv electrons.
5. .\ total of B shored outer-rinq electronsare needed to make a
comoound.
'
;
choice in the space.
1. A compound is formed when outer-ring electrons
2. A compound needs a total of
2.8
separate.link up
outer-ring electrons.
I2
r
lr
trt
Ir
.t'
{:
r.
3. The outer-riag elecfons of a compound come from
oDOatom. two ot mor€
different atoms
The outer rine of a metal has
4.
fewer, more
Metals
5.
electrons.
lend, borrow
The outer ring of a nonmetal has
6.
lgw€r, more
Nonmetals
7,
than four electrons.
lead, borrow
than four eiectrons.
electrons.
Most elements are
8.
ostalr, soD.Eetals
COIVIPI-ETING
]TIE GIARTS
Numberof
Electrons
in Outer
Ring
Element
1. calcium
2. copper
3. phosphorus
4. potassium
5. olrygen
6. iodine
7. gold
8. bromine
__a*__
9. sulfur
10. cobalt
726
In each of the charts below, fill in the missing information.
Use the PeriodicTable to help. The first element,calcium,has
alreadybeen done for you in chart I.
Metal or
Nonmetal?
Electron
Lender or
Borrower?
metal
lender
Lends or
Borrows
How Many
Electrons?
o
t'
T{
3. Tbe outer-ring elecfons of a compound come hom
r
4.
!i
fi
I'
The outer ring of a metal has
5. Metals
6.
than four electrons.
o
electrons.
lend, borrow
The outer ring of a nonmetal has
7. Nonmetals
8.
fewer, roore
ooo 8tom, two or mone
differeDtatons
fgwer. mor€
than four electrons.
electrons.
lend, borrow
Most elements are
mctrlr,
In each of the charts below, fill in the missing information.
Use the PeriodicTable to help. The fi.rstelement,calcium,has
already been done for you in chart I.
COlVtPr ETING
'llIE
G{ARTS
Number of
Electrons
in Outer
Ring
Element
1. calcium
2. copper
3. phosphorus
4. potassium
5. oxygen
6.
iodine
?. gold
8. bromine
9. sulfur
10. cobalt
726
nO.tqgtals
_,-_
Metal or
Nonmetal?
Electron
Lender or
Borrower?
metal
lender
Lends or
Borrows
How Many
Electrons?
if
II.
Lenci
Borrow
Elecuons
Elecuons
(ChooseEitherl
Eiementsoi
Group
IA
/
Mei.ai or
Nonmetal
metal
II
I
IIA
vm fl
IB
trB
VIIA
Notice tbat some of the groups are missing from this chart. This is because some of the groups
contain botb metals and nonmetals.
The steplike black line on the Periodic Table separates the metals from the nonmetals. The
elements to the left of the line are metals. The elements to the right are nonmetals.
The elements in Group O do not lend nor borrow electrons. Becausethev do not combine with
other eiements they are often cailed the noble gases.
PAIRING
SRCL?S
Usethe PeriodicTable to answerthesequestions:
Remembera toto.l of 8 outer electronsare neededto make a
compound.
1. Elementsof GroupIA link up with the elementsof Group
2.
Elements of Group IIA form compounds with the elements of Group
t
3. Atoms of Group IB combine with the atoms of Group
)
)
4.
The elementsthat do not combinewith other elementsare thoseof Group
727
MATCHING
1.
.t
N:fiJ*rtwo
rists.
Write the correct letter on the line next
to
metals
eight
_a)
link up to form water
o
b) link up to form salt
3.
sodium and chlorine
4.
hydrogen and orygen
5.
nonmetals
c) number of outer-ring electrons
needed to form a compound
d ) borrow electrons
e)
lend eiectrons
I
t il
I iii
write T on the line next to the number if
the sentenceis true.
\Vrite F if the sentenceis false.
li
I
I
ti
l,
1.
Atoms with fewer than 4 outer electrons lend
electrons.
2.
Atoms with more than + outer electrons
borrow electrons.
3.
Metals lend electrons.
4,
Nonmetals lend electrons.
5.
Electronsfrom inner shells link up to form
compounds.
6. -
o n l y o u t e r s h e l l s g a i n o r r o s ee r e c t r o n sr v i t h
other
atoms.
All atoms form compounds.
8.
Every element can link up with every other
element.
I
1
I
728
I
J
I
I
1
F
t*
CCMPLETE T}IE DIAGRA4S
a) Fill in the missing parts or inJormauonon each diagrambeiow.
b) Then show how the atoms link up.
-
'u/
f.
t'
(
'=
;
Magnesium
and Orygen
I
:'
I
(Mgl
mqncrium
oxygcn (Ol
,L
t.
Which atom is a) the lender?
b) the borower?
c)
the metal?
d) the nonmetal?
z.
The formula for this compound is MgO. In a compound, the first element is a
mctal. nonmetai
Beryilium arrd Suifur
4p
+
-o
5n
!6ryllium (Bel
B.
sullur (S)
3. \Vhich atom is
a) the lender?
b) the borrower?
c)
the metal?
d) the nonmetal?
4.
What is the formula for this compound?
L29
R.EACHING OUT
a
of'lhef
J:*:'.i:"3:x?i:il:
Calcium and chlorine lin-k up to form calcium chloride.
atoms. Fill in the missing parts on each diagram. Then
.-
M= L--
M= -
L=_
- . x \_
K--\\
@,),li
7
Calcium
1 . How manv outer-ring electronsdoes a calcium atom have?
2 . How many outer-ring electrons does a c h l o r i n e a t o m h a v e ?
3 . lVhich atom lends electrons?
4 . How many electronsdoes one otom of this element lend?
J.
lVhich atom borrows electrons?-
6.
How many electrons does one otom of this element borrow?
How many chlorine atoms are needed to link up with one calcium atom? Explain.
8. What is the formula for caicium chloride?
130
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