53
*»
«
O
M
s
^
S 1.1
S3'a
I$
%%%
* »
o
a*© 3
gS
|
5 o »
CO
H > «B
Q
<* sa
SB
&
ft
©
s
t!
tB
Iff
1
lilt a"
S'g
<6" 'Si
»
1 «"
SIf
ifl
o
SB CU B
III
3
i-S
2L
cu-
OS
^r
SS
0«D
SB ss
* Ou
§ H
cu-
wi
<<
M
o
53
SP
sa
CO
S3
<
!
w
to
w » I.
g
§
fB
O
"S
1
©
O
3
g
El
2
Wi
1
1
1
so
QL_
*•**
s©
•
©
S S < fe^
S3 » »
"S
<»
{3 ag «»< a
S*."^
s
I
©
SSL
£0
&
^
i-t S et>
I
8
1 t f f-«
ft. S a. 1^
pu
8
3
gi
i
:
-1 c>
8:5
3 'I a
a a ^ g a.
D » 3
1 18>
s
I -5 B
3
S-ft
I
1
I
f
I
"
<^4, 5 5
V!
8!
g s; | s-
IS
I
11 "
K
©
Bd
gL
o -si
6 g-
»
g^ 2 si fcj 5' fa
fa S cf
2 o
o"
3
|S|B
If
I
1
52 w'i'
P^
89
&
: 3
\
S
1
Osi
6^
r8-
o
St
I
»
I
s.
"^
m
m
3
m
CD
=!
3
(U
D
3(B
m
&
re
«
m
CD
fT
o>
3
ro
»
t^
o
o
05
SO
s
(D
&
cr
a a.
STMS.
<7
BC
Of
1
I
IS
tu
w
'TJ
rf,
tTQ
O
CJ
O
g
3
»
trt^r
». a.
is
w
I
©
a ©
s3
Sf »
a, ©s
a
s* s 5*
3fa a.
**
s
co JS*
« so
WJ
MM
SB*
CO
sr
e»
s
Q
o llt
Oi.
3
(a
ST
ft
ev* >«t
8g
ra
Ci>
3'
a
H
5
S
T
f
o
g
c*
a*
S"
g
ffl
s.
»
^
XT**
o
Jw
3
c*—,
2
M7
a
!"**
S*
(£
S
ffi
fji
o
L-v)
©
o
-4-1
v«
o
+
a
B
o
o
B
©
I
j».
B
a*
%
&
3
1
e
©
K>
B
w
o
B.
us
3
»
©
13
§
S
cr
<••*•
S3
Atomic Structure - Practice Questions
Experiments performed to reveal the structure of atoms led scientists to conclude that an
atom's
(1) positive charge is evenfy distributed throughout its volume
(2) negative charge is mainly concentrated in its nucleus
(3) mass is evpntyriisfributedthroughout its volume
f (4) volume is mainly unoccupied"
^—
2. The modem mode] of the atom shows that electrons are
v i ' n ^
r
(1) orbiting the nucleus In fixed paths ?\%el) M t i - U - B o K f 4 WOheL
1(7)foundSnligionscalledorbitalil
lAA\JC -MlCHtiAlCAlM^htL
(3)corrShedwith neutrons in the nucleus
(4) located In a solid sphere covering the nucleus
* ®kms MaM-lv/ m}U
I
t
^Hic
3. An experiment in which alpha particles were used to bombard thin sheets of gold foil k
to the conclusion that an atom is composed mostly of "
l^X-JmCx/
(1) empty space and has a small, negatively charged nucleus
^ \
.
-|(2)"empty space and has a small, positively chargedlfudeusl
^^mismtiHT
(sja^large, dense, positively chirgecTnuicIeus
(4) a large, dense, negatively charged nucleus
tM
4. What Is the atomic number of an element that has six orotons and eight neutrons?)
(Til?)
(2)2
(3)8
(p
(4)14
I
5. An atom of fluorine has a mass of 19 atomic mass units. The total number of protons
and neutrons in its nucleus is
(2)10
(4)28
(3)19
(1)9
c
—i
6. Whit is the total number of protons contained in the nucleus of a carbon-14 atom? 6t*a)WiS
IW6)
(2)8
(3)12
(4)14
<jj
fl^fyO^
7. JSatisthe nuclear charge of an iron atom? r £ ,
p)+26l
(2)+30
(3)+56
f oo|( Scf- ( U w i SC fliU^fcur
(4)+82
8. Which of these elements has an atom with the most stable outer electron configuration^f (^0 ffsP \iru
^3l"l
1
z
raa>?--*
(3)Ca^H>l (4)Na ^ - |
fty..^^
9, How many electrons are in the outermost principal energy level of an atom of carbon in
the ground state?
2-" M
(1)6
(2)2
'
(3)3
'((4)4
10. Which electron configuration is correct for a sodiumton?| o ^ |f5 \/ft.|ty\ if e If {.fnvl
(1)2-7
I (2)T^
(3)2-8-1 (4)2-8-2
11, What is the electron configuration of a sulfur atom in the ground state?
(1)2-4
(2)2-6
13)-23PF
MlSt)
tf
(/
\fi\im
*
•tit c m
l\\ r. L
^ 7
tf A \
""^
12 The nucleus of which atom contains 48 neutrgjs?
(4) ™Cd
iU ti
13 The number of neutrons in the nucleus of an atom can be determined by
(1) adding the atomjcrtumber to the mass number
iJ^^ffi^^ffig^^^^^^n^teF^m^^^SjruMnber
(P)iddihg the^T^TmnKiFtottie atonicmi^
(4) subtracting the mas number from tie atomic number
z
,
1
14 When an Vtom lose^nelecfa^^ie atom becomes an ion that Is lh\l
|H
1
f\la(A^h^t
(1) j^^HveE^char^dat^ffins a small amount of mass
t
O^TS^Svilvcliir^land iosesasmall amountoTmasiO
(3) negatively charged and gains a small amount of mass
(4) negatively charged and loses a small amount of mass
15, In which pair of elements do the nuclei of the atoms contain the same number of^
neutrons? L^%- Pof 5eu<M_ A l ^ F ^ T H ^ ^ r ^
(1) lu and *Be ^ ^ %(2) »iV and " o 1 ^
g
(4) »5 and »C7 l^. w^J ll
16-The characteristic spectral lines of elements are caused when electrons in an excited
atom move from
iL z-Ti i A \f ' T l j / f
(1) lower to higher energy levels, releasing energy
/^ O liAIJ / I *[ I o
(2) lower to higher energy levels, absorbing energy
/
"ts^gpTWlpg^ratetiyTeveis, releasing energy"
^"highertoTowerCTiSlTTsvelsTa^SrBing energy
17. Which lewis electron-dot structure is drawn correctly fortiieatom it represents?
S
18,When a liOiium atom fornis a Li+ Son, the lithium atom io^.S &^A € Ucjiw
(1) gains a proton
r(3)jos^an electrurr\
(2) loses a proton
l^T^Ri'ine'ectron
3
19, What is the total number of electrons in the valence shell of an atom of aluminum in tfie
ground state? Z . ' S " ^
r—
(1)8
(2)2
(3)3
(4)10
20,to electron in an atom movesfromthe ground state to an excited state when ttie energy
| (1) increases"^
(2) decreases
(3) remains the same
f"0
21, During a flame test, ions of a specific metal are heated in theflameof a gas burner. A
characteristic color of light is emitted by these ions Intiieflamewhen the electrons
(1) emit energy as they move to higher energy levels
£*—"—"•
7 (2) emit energy as they return to lower energy levels |
(^gairTeftet^yisThey move to higher energylevels
(4) gain energy as they return to lower energy levels
L
22, What is the total number of electrons In a Cu+ ion? LiPr
7
(1) 36
(2) 29
(3) 30
_ n
¥4) 28 /
Base your answers to questions 23 and 24 on the information and the bright-line spectra
represented below.
Many advertising signs depend on the production of light emissions from ga$-filfedglass
tubes that are subjected to a high-voliage source. When light emissions are passed
through a spectroscope, bright-line spectra are produced.
OasA
SssB
] \^
QsssG
QasD
LMsrowr, r
23. Identify the two gases in the unknown mixture. fL Ar
A
f)Ab b
24. Explain ifte production of an emission spectrum In terms of the energy states of an electron.
U^htvi OuA tkchoA dbSofbs u\im\t i-f jui^pi f> (Lnifo
if dropi bad/ do^fi h G< Mcrt ih^kit tltcbw
h\f dfoff^m k a. /ovo«/ wyf
(a^fi^eJioA
hfto1
'^ tod njtc^o a j^kUn
if i^w u)hu9 itrdm fas wj\f-
I^
Topic 1 The Atom - Review Sheet Part I
Part I - Multiple Choice Questions
I
1 Which two particles have approximately the same mass?
Q) proton and neutron "jj © H, J ^ j ^ ^
(3) neutron and electron
(2) proton and electron
(4) neutron and positron
£_/ 2 Which statement is true about a proton and an electron?
(1) They have the same masses and the same charges,
(2) They have the same masses and different charges.
(3) They have different masses and the same charges.
(3j)They have different masses and different charges.
3
3
3 The atomic mass of an element is the weighted average of the masses of
(1) its two most abundant isotopes
@>^ of its naturally occurring isotopes
(2) its two least abundant isotopes
(4) all of its radioactive isotopes
4 Which statement is true about the charges assigned to an electron and a proton?
(1) Both an electron and a proton are positive.
(~~)
^ps
(2) An electron is positive and a proton is negative.
^-^
jpp) An electron is negative and a proton is positive.
0 AlfUA. |40Ha
(4) Both an electron and a proton are negative.
.
/"nCLf^C
J
WCljS
statement best explains why most atomic masses on the Periodic Table are decimal numbers?
3 (2)5(1)Which
Atomic masses are determined relative to an H-l standard.
Atomic masses are determined relative to an 0-16 standard,
I?) Atomic masses are a weighted average of the naturally occurring isotopes.
(4) Atomic masses are an estimated average of the artificially produced isotopes.
has a charge of "" 1
3 6(1)(2)An~3+1electron
and die same mass as a proton
and the same mass as a proton
OCHV
Qs~l- and a smaller mass than a proton
(4) +1 and a smaller mass than a proton
7 In which compound is the percent by mass of oxygen greatest?
(I)BeO
(2)MgO
(3)CaO
(4)SrO
$ The atomic number of an atom is always equal to the number of its
(T) protons, only
(3) protons plus neutrons
(2) neutrons, only
(4) protons plus electrons
9 Which subatomic particle has no charge?
(1) proton
(rojiieutron
3
(3) the nucleus
(4)electrorL
10 The atomic mass of an element is calculated using the
(1) atomic number and the ratios of its naturally occurring isotopes
(2) atomic number and the half-Hves of each of its isotopes
^3) masses and the ratios of its naturally occurrmg isotopes
(4) masses and the half-lives of each of its isotopes
TNiM 1V •" ^"e percent by mass of calcium in the compound calcium sulfate (CaSOi) is approximately
\ J ' m (1)15%
(2)29%
(3)34%
(4)47%.
I
L
12 Which statement best describes electrons?
(1) They are positive subatomic particles and are found in the nucleus.
(2) They are positive subatomic particles and are found surrounding the nucleus.
(3) They are negative subatomic particles and are found in the nucleus
fH They are negative subatomic particles and are found su* rounding the nucleus.
m\ I
••s
/_
3 What is the percent by mass of oxygen in H2SO4 ? [formula mass = 98]
1)56%
(2)33%
(3)65%
(4)98%
14 Art atom of carbon-12 and an atom of carbon-14 differ in
^ h j ^ k{X0£ *> f
M
atomic
number
(3)
nuclear
charge
-* ., , ll rr
(1)
^ '
mass number
(4) number of electrons W b«Pf • ^ * . ^
©
^^^
A^OC^M^
A£a.htM. ,
'
,.
15 Subatomic particles can usually pass undetected through an atom because the volume of an atom
Is composed of
Q) an uncharged nucleus
(3) neutrons
ra largely empty space
(4) protons
16WhatisthetotaInumberofprotonsinthenucleusofanatomofpotassium-42?
(1)15
^5)19 - ^
(3)39
(4)42
Z
'-j
L,
msVl/C
1? Which electron configuration is correct for a potassium ion? 2 r ? ' ^ ~ l ~ ffitM
(1)2-7
||£-8-S
(3)2-8-1
(4)2-8-2
,/
ItsXPA I
i/e
IC l<*^ ' ^
18 As a Ca atom changes to Ca2* , the number of neutrons in its nucleus
(1) decreases
(2) increases
^ remains the same (4) doubles
-? 19 All the isotopes of a given atom have
X (I) the smne mass number and the same atomic number
— (2) the same mass number but different atomic numbers
^different mass numbers but: the same atomic number
(4) different mass numbers and different atomic numbers
~ jT
"y _ 9 - ^
XcMS Ml XU. (0*.W
/ - \ . "^ ^ ^ f
ACMAf/)^!
^
,
J
J
„ - ^.n /^i
^
/J '
^
\ 20 The percent by mass of hydrogen in NHs is equal to
^ %m
m ^ X 180
U
(3) -^ x JOG
1,4) ^ x 100
21 Which particles are found in the nucleus of an atom?
(1) electrons, only
(3) protons and electrons
<2) neutrons, only
^protons and neutrons
<? ' "
/g t" (U> ft^l WA
22 Which symbol represents a particle that has the same total number of electrons as S *?
^lee-
3
i4e"
stc-
nt-
J
23 A sample of a substance containing only magnesium and chlorine was tested in the
laboratory and was found to be composed of74.5% chlorine by mass, if the total mass of the
sample was 190.2 grams, what was the mass of the magnesium?
(l)24.3g
(2) 48.5 g
(3) 70.9 g
(4)142g
24 What is the total number of electrons found in an atom of sulfur?
(4)32
(1)6
(2)8
©36^~
f
|
' I
;
j
^
5^
C®
|
25 The nucleus of an atom of cobalt-58 contains
CD 2 7 protons and 31 neutrons
(3) 59 protons and 60 neutrons
(2) 27 protons and 32 neutrons
(4) 60 protons and 60 neutrons
27 f4 .
26 How many electrons are contained in an Au1"3 ion? M+ f?C~
%76
(2)79
(3)82
(4)179
|
27 What is the total number of electrons in a Cr ^ ion? /o^ -I Z? "
21(' 3 " 2. J
(1)18
|2))21
(3)24
(4)2?
28 What Is the total number of neutrons in an atom of an element that has a mass number of 19 and
an atomic number of 9?_
10 . Q _ i^
(4)28
(3)19
0)9
mm
| 29 The nucleus of an atom of K-42 contains
© 19 protons and 23 netrtrons
(2) 19 protons and 42 neutrons
^ i /
(3) 20 protons and 19 neutrons
j^
(4) 23 protons and 19 neutrons jQ
11^
30 What is the total number of electrons in a Cu* ion? (tM J £ "
©£8
(2)29
(3)30
21-l-.iSWM
3
31 As an atom becomes an ion, its mass number
(1) decreases
(2) increases
/(§) remains die same
# ETfeeJmA tao« \f\<^^k
ri 32 The number of neutrons in the nucleus of mi atom can be determined by
/__{!) adding the atomic number to the mass number
I subtracting the atomic number from the mass number
(5) adding the mass number to the atomic mass
(4) subtracting the mass numberfromthe atomic number
t)<AvV
33 The gramformulamass of NH4CI is
(I) 22.4 g/mole
(2) 28.0 g/mole
(3) 53,5 g/moie
po MSS/Ortltj^^WjC
(4) 95.5 gtoole
34 A compound has a gram formula mass of 180 grams per mole. What is the molecular formula
'Qvll'T for this compound?
(l)C6HiaOi
(2)C«Ha2Qn
(3)C3H6
(4) QHj
Part 11 Type Questions
In the modem model of the atom, each atom is composed of three major subatomic (or fttndamental)
particles.
\
1
35 Name the subatomic particles contained in the nucleus of the atom, fl] P ^>TWi ^ $ ^ fl. y\6 U Wftfl
36 State the charge associated with each type of subatomic particle contained in the nucleusofthe atom.
37 What is the net charge of the nucleus? [\\
Base yoar aaswers to qaestions 38 through 40 on the data table below, which shows three isotopes
of neon.
Atoraic Mass
Percent f-iataral
(atoimlc mass unftsj
90.9%
20.9S
0.3%
21 as
8.6%
Isotope
wm
<x>m
'Me
s
^Ne
38 In terms of atomic particles, state one difference between these three isotopes of neon, [l]
39 Based on the atomic masses and the natural abundances shown in the data table, in the
space provided below, show a correct numerical setup for calculating the average atomic mass of neon.
40 Based on natural abundances, the average atomic mass of neon is closest to which whole number? [i]
/Q
Base yoor answers to questions 41 and 42 on the informatiott below.
Naturally occurring elemental carbon is a mixture of isotopes. The percent composition
of the two most abundant isotopes is listed below.
• 98.93% of the carbon atoms have a mass of 12,00 atomic mass units.
* 1.07% of the carbon atoms have a mass of 13.00 atomic mass units.
41 In the space provided below, show a correct numerical setup for calculating the average atomic mass
of carbon. W ^ ^ ^ Q O ^ ^ )
^
C j ^ M ^ ^ ^ ' /0£>
(oO
42 Describe, in terms af subatomic particlesfound in the nucleus, one difference between
the nuclei of carbon-12 atoms and the nuclei of carbon-13 atoms. The response must include both
isotopesW
^ - '
/ feu niaUA fkw L-li M ih W ^ j
ot
C~I3 mb / w At afron
JTA
f-f'i
HUCJ/MA $IM A
('It
43 In the early 1900s, experiments wore conducted to determine the structure of the atom. One of these
experiments involved bombarding gold foil with alpha particles. Most alpha particles passed directly
through the foil. Some, however, were deflected at various angles. Based on this alpha particle
experiment, state two conclusions that were made concerning the structure of an atom. [2] /y0 £>} 1 ^
44 Show a correct numerical setup for calculating the formula mass of glucose, €$H ^Oe. [! ]
DM i f
4
ai^,
Ji
< '
-J- iW- iftlX Cm]
I ^—^
!
'
Topic 1 Review Sheet Part II
Part A Type Questions
|
1 As an electron in an atom moves from the ground state to the excited state, the electron
S(|) gains energy as it moves to a higher energy level
(2) gains energy as it moves to a lower energy level
(3) loses energy as it moves to a higher energy level
(4) loses energy as it moves to a lower energy level
(
2 In the wave-mechanical model, an orbital is a region of space in an atom where there is
%& a high probability offindingan electron
(2) a high probability offindinga neutron
(3) a ckcular path in which electrons are found
(4) a circular path in which neutrons are found
I 3 Which electron transition represents a gain of energy? l & w i* '
t l ^ from 2nd to 3rd shell ^ 3
(3) from 3rd to 2nd shell P*
(2) from 2nd to 1st shell jOo
( 4 from 3rd to 1st shell p *
1
U
j
4 Which Lewis electron-dot structure is drawn correctly for the atom it represents?
(1) :N
(2) ; F :
(3) 'P :
H
5 The region that is the most probable location of an electron in an atom is
*— (I) the nucleus
p ) a n orbital
(3) the excited state
o
/«
dflfjs tm:
(4) an ion
O 6 What is the total number of electrons in the valence shell of an atom of aluminum in the
•-} ground state?
^-^
(1)8
(2)2
g))
(4)10
"7
q
7 Which electron configuration is correct for a sodium ion? N ^ ^ . fo'&SC A.4 O ^ s M T f i M SfaJt
(1)2-7
p\2-8
(3)2-8-1
(4)2-8-2
}
8 What is die electron sonfigtttatkon of a sulfur atom in the ground state? 2,' o~ ^
(1)2-4
(2)2-6
"
(3J2-8-4
@)2-8-6
1
9 The modem model of the atom shows that electrons are
Q) orbiting the nucleus infixedpaths
^jj found in regions called orbitals
(3) combined with neutrons in the nucleus
(4) located in a solid sphere covering the nucleus
3
10 During a flame test ions of a specific metal are heated in the flame of a gas burner. A characteristic
color of light is emitted by these tens in the flame when the electrons
(1) gain energy as they return to lower energy levels
(2) gain energy as they move to higher energy levels
)emit energy as they return to lower energy levels
) emit energy as they move to higher energy levels
f
r
oi
"x
Part B-l Type Questions
11 Which electron configuration represents the electrons of an atom in an excited slate?
(1)2-4
(2)2-6
fiM-l-l
(4)2-8-2
3
12 Which electron configuration represents an atom of chlorine in an excited state?
(1)2-8-7
(2}>*-fr/@>-8-6-I
(4>3=8^7-l
2-?-"! " Gro^ci
13 Which ion has the same electron configuration as an atom of He?
<2)0'
(3)N»
(4)Ca-
I
PartC
14 In the space provided onyow ans\vgr sheet, draw a Lewis electron-dot structure for
an atom of phosphorus, [t] 2.-R'[V
^ ^OlicMff t k c W - i
*T
2S
Base your answers to questions 15 and 16 on the diagram below, which shows bright-line
spectra
of selected elements.
Bright«Line Spectra
H
He
£\
E
17
iU
Unknown
15 Identify the two elements in the unknown spectrum. [2} 4-
•- P
16 Explain how a bright-line spectrum is produced, in terms of excited state, energy
,
. I
tmmitmns, m^gromdstate. [2] oC^ey? Itrl d ^ c N * (XhSwhSfi^erqc),/ i 1 M *• D i TO ^ /l/Q M r
o/^'Ki MCS is IA fit ta/*((sKle.%!), ^A uM5M(r J 4tf irht tluhcvs
17 Irs the box providea <*« J^OM?-fiawer s^/i'/draw the electron-dot (Lewis) structure
of an atom of calcium, [i]
y^*
18 In the box provided on your answer sheet, draw the electron-dot (Lewis) structure
of an atom of chlorine, [ij
a
VT
'
H'
v
IJtuZ&J
VL
"
u
jr«-7r.