Upload
asd
View
230
Download
0
Embed Size (px)
Citation preview
7/24/2019 Ch25 Lesson25_2
1/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
1 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
Chapter 25uclear Che!istry
25.1 uclear Radiation
25.2 Nuclear Transformations
25." #ission and #usion
25.$ Radiation in %our &ife
7/24/2019 Ch25 Lesson25_2
2/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
2 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
What is the source of radon in homes?
CHEMISTR!"#
Radon !ay
accu!ulate in a'ase!ent that is
not (ell ventilated.
)est *its are
availa'le to
!easure the
levels of radon in a 'uilding.
7/24/2019 Ch25 Lesson25_2
3/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
" Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
uclear +ta'ility anduclear +ta'ility and
ecayecay
Nuclear Sta$ilit% and &eca%
-hat deter!ines the type of decay a
radioisotope undergoes
7/24/2019 Ch25 Lesson25_2
4/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
$ Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
uclear +ta'ility anduclear +ta'ility and
ecayecay
)he nuclear forceis an attractive force
that acts 'et(een allnuclear particles that
are e/tre!ely close together, such as
protons and neutrons in a nucleus.
7/24/2019 Ch25 Lesson25_2
5/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
5 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
uclear +ta'ility anduclear +ta'ility and
ecayecay
)he nuclear forceis an attractive force
that acts 'et(een allnuclear particles that
are e/tre!ely close together, such as
protons and neutrons in a nucleus.
0 At these short distances, the nuclear force
do!inates over electro!agnetic repulsions
and holds the nucleus together.
7/24/2019 Ch25 Lesson25_2
6/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
)he sta'ility of a nucleus depends on theratio of neutrons to protons.
Inter'retata
0 )his graph
sho(s thenu!'er of
neutrons vs. the
nu!'er of
protons for all
*no(n sta'le
nuclei.
7/24/2019 Ch25 Lesson25_2
7/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
)he sta'ility of a nucleus depends on theratio of neutrons to protons.
Inter'retata
0 )he region of the
graph in (hichthese points are
located is called
the $and of
sta$ilit%.
7/24/2019 Ch25 Lesson25_2
8/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
3 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
)he sta'ility of a nucleus depends on theratio of neutrons to protons.
Inter'retata
0 #or ele!ents of lo(
ato!ic nu!'er4'elo( a'out 26,
this ratio is a'out 1.
0 A'ove ato!ic
nu!'er 2, sta'lenuclei have !ore
neutrons than
protons.
7/24/2019 Ch25 Lesson25_2
9/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
7 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
uclear +ta'ility anduclear +ta'ility and
ecayecay
A nucleus !ay 'e unsta'le and undergo
spontaneous decay for different reasons.
)he neutron8to8proton ratio in aradioisotope deter!ines the type of decay
that occurs.
7/24/2019 Ch25 Lesson25_2
10/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
1 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
uclear +ta'ility anduclear +ta'ility and
ecayecay
+o!e nuclei are unsta'le 'ecause they
have too !any neutrons relative to thenu!'er of protons.
0 -hen one of these nuclei decays, a neutron
e!its a 'eta particle 4fast8!oving electron6 fro!the nucleus.
7/24/2019 Ch25 Lesson25_2
11/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
11 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
uclear +ta'ility anduclear +ta'ility and
ecayecay
+o!e nuclei are unsta'le 'ecause they
have too !any neutrons relative to thenu!'er of protons.
0 -hen one of these nuclei decays, a neutron
e!its a 'eta particle 4fast8!oving electron6 fro!the nucleus.
9 A neutron that e!its an electron 'eco!es a proton.
n1
p :1
1 e
91
7/24/2019 Ch25 Lesson25_2
12/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
12 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
uclear +ta'ility anduclear +ta'ility and
ecayecay
+o!e nuclei are unsta'le 'ecause they
have too !any neutrons relative to thenu!'er of protons.
0 -hen one of these nuclei decays, a neutron
e!its a 'eta particle 4fast8!oving electron6 fro!the nucleus.
9 A neutron that e!its an electron 'eco!es a proton.
n1
p :1
1 e
91
9 )his process is *no(n as 'eta e!ission.
9 It increases the nu!'er of protons (hile
decreasing the nu!'er of neutrons.
7/24/2019 Ch25 Lesson25_2
13/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
1" Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
uclear +ta'ility anduclear +ta'ility and
ecayecay
Radioisotopes that undergo 'eta e!ission
include the follo(ing.
Cu
27 ;n :
" e
91
C1$
:1$
e
91
7/24/2019 Ch25 Lesson25_2
14/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
1$ Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
uclear +ta'ility anduclear +ta'ility and
ecayecay
7/24/2019 Ch25 Lesson25_2
15/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
15 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
uclear +ta'ility anduclear +ta'ility and
ecayecay
A 'ositronis a particle (ith the !ass of anelectron 'ut a positive charge.
0 Its sy!'ol is e.
0 uring positron e!ission, a proton changes toa neutron, =ust as in electron capture.
:1
>3
5 >e :3
$ e
:1
25.2 Nuclear Transformations >
1 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
uclear +ta'ility anduclear +ta'ility and
ecayecay
uclei that have an ato!ic nu!'er greater
than 3" are radioactive.
0 )hese nuclei have 'oth too !any neutrons and
too !any protons to 'e sta'le.
9 )herefore, they undergo radioactive decay.
9 Alpha e!ission increases the neutron8to8proton
ratio, (hich tends to increase the sta'ility of the
nucleus.
0 ?ost of the! e!it alpha particles.
7/24/2019 Ch25 Lesson25_2
17/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
1 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
uclear +ta'ility anduclear +ta'ility and
ecayecay
In alpha e!ission, the !ass nu!'er
decreases 'y four and the ato!ic nu!'er
decreases 'y t(o.
Ra22
33 Rn : @e222
3
$
2
)h2"2
7 Ra : @e223
33
$
2
+
7/24/2019 Ch25 Lesson25_2
18/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
13 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
uclear +ta'ility anduclear +ta'ility and
ecayecay
Recall that conservation of !ass is an
i!portant property of che!ical reactions.
0 In contrast, !ass is not conserved duringnuclear reactions.
0 An e/tre!ely s!all uantity of !ass is
converted into energy released duringradioactive decay.
7/24/2019 Ch25 Lesson25_2
19/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
17 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
&urin( nuclear deca%) if the atomicnum$er decreases $% one $ut the mass
num$er is unchan(ed) the radiation
emitted is
*. a positron.
+. an alpha particle.
C. a 'eta particle.
&. a proton.
7/24/2019 Ch25 Lesson25_2
20/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
2 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
&urin( nuclear deca%) if the atomicnum$er decreases $% one $ut the mass
num$er is unchan(ed) the radiation
emitted is
*. a 'ositron.
+. an alpha particle.
C. a 'eta particle.
&. a proton.
7/24/2019 Ch25 Lesson25_2
21/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
21 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
@alf8&ife@alf8&ife
Half,-ife
@o( !uch of a radioactive sa!ple
re!ains after each half8life
7/24/2019 Ch25 Lesson25_2
22/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
22 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
1
2A half,life4t 6 is the ti!e reuired for one8half of the nuclei in a radioisotope sa!ple
to decay to products.
Inter'retBraphs
After each half8
life, half of the
original
radioactive
ato!s havedecayed into
ato!s of a ne(
ele!ent.
7/24/2019 Ch25 Lesson25_2
23/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
2" Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
@alf8&ife@alf8&ife
@alf8lives can 'e as short as a second or as
long as 'illions of years.
Half,-ies of Some Naturall% "ccurrin( Radioisoto'es
Isoto'e Half,life Radiation emitted
Car'on81$ 5." 1"years
Potassiu!8$ 1.25 17years ,
Radon8222 ".3 days
Radiu!822 1. 1"years ,
)horiu!82"$ 2$.1 days ,
Draniu!82"5 . 13years ,
Draniu!82"3 $.5 17years
Com'arin( Half,-ies
7/24/2019 Ch25 Lesson25_2
24/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
2$ Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
@alf8&ife@alf8&ife
0 +cientists use half8lives of so!e long8ter!
radioisotopes to deter!ine the age of ancient
o'=ects.
0 ?any artificially produced radioisotopes have
short half8lives, (hich !a*es the! useful in
nuclear !edicine.
9 +hort8lived isotopes are not a long8ter!
radiation haard for patients.
Com'arin( Half,-ies
7/24/2019 Ch25 Lesson25_2
25/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
25 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
@alf8&ife@alf8&ife
Com'arin( Half,-ies
0 )he age of uraniu!8
containing !inerals can 'eesti!ated 'y !easuring
the ratio of uraniu!82"3 to
lead82.
0 >ecause the half8life of
uraniu!82"3 is $.5 17
years, it is possi'le to use
its half8life to date roc*s as
old as the solar syste!.
Draniu!82"3 decays through a co!ple/ series of
unsta'le isotopes to the sta'le isotope lead82.
7/24/2019 Ch25 Lesson25_2
26/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
2 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
#ranium com'ounds are found inroc/s and in soils that form from theseroc/s. Ho0 can these uranium
com'ounds lead to a $uildu' of radonin homes and other $uildin(s?
CHEMISTR!"#
7/24/2019 Ch25 Lesson25_2
27/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
2 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
#ranium com'ounds are found inroc/s and in soils that form from theseroc/s. Ho0 can these uranium
com'ounds lead to a $uildu' of radonin homes and other $uildin(s?
CHEMISTR!"#
Radon gas is a product of the decay of
uraniu!. As the uraniu! co!pounds in
the soil 'eneath ho!es and 'uildings
decay, radon is produced and seeps into
the structure.
7/24/2019 Ch25 Lesson25_2
28/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
23 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
@alf8&ife@alf8&ife
Radiocar$on &atin(Plants use car'on dio/ide to producecar'on co!pounds, such as glucose.
0 )he ratio of car'on81$ to other car'on isotopesis constant during an organis!Fs life.
0 -hen an organis! dies, it stops e/changing
car'on (ith the environ!ent and its radioactive C ato!s decay (ithout 'eing replaced.
0 Archaeologists can use this data to esti!ate
(hen an organis! died.
1$
2 2 N l T f i
7/24/2019 Ch25 Lesson25_2
29/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
27 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
@alf8&ife@alf8&ife
E1'onential &eca% unction
0 Astands for the a!ount re!aining.
0 Astands for the initial a!ount.
0 nstands for the nu!'er of half8lives.
%ou can use the follo(ing euation to
calculate ho( !uch of an isotope (ill
re!ain after a given nu!'er of half8lives.
AG A1
2
n
25 2 N l T f ti
7/24/2019 Ch25 Lesson25_2
30/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
" Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
@alf8&ife@alf8&ife
0 )he e/ponent nindicates ho( !any ti!es A
!ust 'e !ultiplied 'y to deter!ine A.1
2
AG A1
2
n
E1'onential &eca% unction
25 2 N l T f i25 2 N l T f ti f f
7/24/2019 Ch25 Lesson25_2
31/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
"1 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
@alf8&ife@alf8&ife
&eca% of Initial *mount 3A4 of
Radioisoto'e
Half,-ife *mount Remainin(
A 4 6G A
1 A 4 61G A
2 A 4 62G A
)his ta'le sho(s e/a!ples in (hich
nG 1 and nG 2.
E1'onential &eca% unction
12
12
12
12
12
12
25 2 N l T f ti25 2 N l T f ti
7/24/2019 Ch25 Lesson25_2
32/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
"2 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
#sin( Half,-ies in Calculations
Sam'lePro'le! 25.1
Car'on81$ e!its 'eta radiation and decays (ith a
half8life 4t 6 of 5" years. Assu!e that you start
(ith a !ass of 2. 1912g of car'on81$.
12
a. @o( long is three half8lives
$. @o( !any gra!s of the
isotope re!ain at the end ofthree half8lives
25 2 N l T f ti25 2 N l T f ti >
7/24/2019 Ch25 Lesson25_2
33/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
"" Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
6N"WNS #N6N"WNS
" half8lives G years
!ass re!aining G g
*nal%7e -ist the /no0ns and the un/no0ns.8
Sam'lePro'le! 25.1
0 )o calculate the length of three half8lives,
!ultiply the half8life 'y three.
0 )o find the !ass of the radioisotope
re!aining, !ultiply the original !ass 'y for
each half8life that has elapsed.
12
t G 5" years
initial !ass 4A6 G 2. 1912 g
nu!'er of half8lives 4n6G "
12
25 2 N l T f ti25 2 N l T f ti > S
7/24/2019 Ch25 Lesson25_2
34/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
"$ Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
a. ?ultiply the half8life of car'on81$ 'y
the total nu!'er of half8lives.
Calculate Sole for the un/no0ns.2
Sam'lePro'le! 25.1
t nG 5" years " G 1,17 years12
25 2 N l T f ti >25 2 N l T f ti > S l P 'l 25 1
7/24/2019 Ch25 Lesson25_2
35/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
"5 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
Calculate Sole for the un/no0ns.2
Sam'lePro'le! 25.1
$. )he initial !ass of car'on81$ is
reduced 'y one8half for each half8life.
+o, !ultiply 'y three ti!es.12
Re!aining !ass G 2. 1912g 12
12
12
G .25 1912g
G 2.5 191"g
25 2 N l T f ti >25 2 N l T f ti > S l P 'l 25 1
7/24/2019 Ch25 Lesson25_2
36/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
" Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
Calculate Sole for the un/no0ns.2
Sam'lePro'le! 25.1
$. %ou can get the sa!e ans(er 'y
using the euation for an e/ponential
decay function.
G 42. 1912g6
G .25 1912g
G 2.5 191"g
AG A G 42. 1912g64 612
n 4 612"
4 61
3
25 2 N l T f ti >25 2 Nuclear Transformations > S l P 'l 25 1
7/24/2019 Ch25 Lesson25_2
37/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
" Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
Ealuate&o the results ma/e sense?
9
Sam'lePro'le! 25.1
0 )he !ass of car'on81$ after three half8lives
should 'e one8eighth of the original !ass.
0 If you divide 2.5 191"g 'y 2. 1912g,you (ill get 12.5H, or .13
25 2 N l T f ti >25 2 Nuclear Transformations >
7/24/2019 Ch25 Lesson25_2
38/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
"3 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
The half,life of 'hos'horus,92 is8:.9 da%s. Ho0 man% milli(rams of
'hos'horus,92 remain after 844.8
da%s if %ou $e(in 0ith 2.5 m( of theradioisoto'e?
25 2 Nuclear Transformations >25 2 Nuclear Transformations >
7/24/2019 Ch25 Lesson25_2
39/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
"7 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
The half,life of 'hos'horus,92 is8:.9 da%s. Ho0 man% milli(rams of
'hos'horus,92 remain after 844.8
da%s if %ou $e(in 0ith 2.5 m( of theradioisoto'e?
nG 1.1 days G half8lives1 half8life
1$." days
G 42.5 !g6 G 2. 192!g
AG A G 42.5 !g64 612
n 4 612
4 6 1123
25 2 Nuclear Transformations >25 2 Nuclear Transformations > )rans!utation Reactions)rans!utation Reactions
7/24/2019 Ch25 Lesson25_2
40/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
$ Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
)rans!utation Reactions)rans!utation Reactions
Transmutation Reactions
-hat are t(o (ays in (hich
trans!utation can occur
25 2 Nuclear Transformations >25 2 Nuclear Transformations > )rans!utation Reactions)rans!utation Reactions
7/24/2019 Ch25 Lesson25_2
41/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
$1 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
)rans!utation Reactions)rans!utation Reactions
#or thousands of years, alche!ists tried
to change lead into gold.
0 -hat they (anted to achieve is
transmutation, or the conversion of an ato!
of one ele!ent into an ato! of another
ele!ent.
25 2 Nuclear Transformations >25 2 Nuclear Transformations > )rans!utation Reactions)rans!utation Reactions
7/24/2019 Ch25 Lesson25_2
42/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
$2 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
)rans!utation Reactions)rans!utation Reactions
)rans!utation can occur 'y radioactive
decay, or (hen particles 'o!'ard the
nucleus of an ato!.0 )he particles !ay 'e protons, neutrons,
alpha particles, or s!all ato!s.
25 2 Nuclear Transformations >25 2 Nuclear Transformations > )rans!utation Reactions)rans!utation Reactions
7/24/2019 Ch25 Lesson25_2
43/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
$" Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
)rans!utation Reactions)rans!utation Reactions
Ernst Rutherford perfor!ed the earliest
artificial trans!utation in 1717.
0 @e 'o!'arded nitrogen gas (ith alpha
particles.
0 )he unsta'le fluorine ato!s uic*ly decay tofor! a sta'le isotope of o/ygen and a proton.
< :1
3 p1
1#13
7
Proton25 2 Nuclear Transformations > )rans!utation Reactions)rans!utation Reactions
7/24/2019 Ch25 Lesson25_2
44/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
$$ Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
)rans!utation Reactions)rans!utation Reactions
RutherfordFs e/peri!ent eventually led to
the discovery of the proton.
0 @e and other scientists noticed a pattern as they did
different trans!utation e/peri!ents. @ydrogen nuclei(ere e!itted.
0 +cientists realied that these hydrogen nuclei 4protons6
!ust have a funda!ental role in ato!ic structure.
@e
Alphaparticle
itrogenato!
#
Dnsta'lefluorine ato!
)rans!utation Reactions)rans!utation Reactions
7/24/2019 Ch25 Lesson25_2
45/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
$5 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
)rans!utation Reactions)rans!utation Reactions
a!es Chad(ic*Fs discovery of theneutron in 17"2 also involved a
trans!utation e/peri!ent.
0 eutrons (ere produced (hen 'erylliu!87
(as 'o!'arded (ith alpha particles.
C :12
n1
eutronCar'on812
>e :7
$ @e$
2
>erylliu!87 Alphaparticle
25 2 Nuclear Transformations >25 2 Nuclear Transformations > )rans!utation Reactions)rans!utation Reactions
7/24/2019 Ch25 Lesson25_2
46/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
$ Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
)rans!utation Reactions)rans!utation Reactions
Ele!ents (ith ato!ic nu!'ers a'ove 72,the ato!ic nu!'er of uraniu!, are called
transuranium elements.
0 one of these ele!ents occurs in nature.
0 All of the! are radioactive.
0 All transuraniu! ele!ents undergotrans!utation.
25 2 Nuclear Transformations >25 2 Nuclear Transformations > )rans!utation Reactions)rans!utation Reactions
7/24/2019 Ch25 Lesson25_2
47/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
$ Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
)rans!utation Reactions)rans!utation Reactions
)ransuraniu! ele!ents are synthesied in nuclear
reactors and nuclear accelerators.0 Reactors produce 'ea!s of lo(8
energy particles.
0 Accelerators are used to increase
the speed of 'o!'arding
particles to very high speeds.
9 )he European
7/24/2019 Ch25 Lesson25_2
48/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
$3 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
)rans!utation Reactions)rans!utation Reactions
0 -hen uraniu!82"3 is 'o!'arded (ith the relatively
slo( neutrons fro! a nuclear reactor, so!e uraniu!nuclei capture these neutrons. )he product is uraniu!8
2"7.
0 Draniu!82"7 is radioactive and e!its a 'eta particle.)he other product is an isotope of the artificial
radioactive ele!ent neptuniu! 4ato!ic nu!'er 7"6.
0 eptuniu! is unsta'le and decays, e!itting a 'eta
particle and a second artificial ele!ent, plutoniu!
4ato!ic nu!'er 7$6.
p :2"7
7" e
91D2"7
72
D :2"3
72 n1
D2"7
72
Pu :2"7
7$ e
91p2"7
7"
25 2 Nuclear Transformations >25 2 Nuclear Transformations > )rans!utation Reactions)rans!utation Reactions
7/24/2019 Ch25 Lesson25_2
49/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
$7 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
)rans!utation Reactions)rans!utation Reactions
+cientists in >er*eley, California,synthesied the first t(o artificial ele!ents
in 17$.
0 +ince that ti!e, !ore than 2 additionaltransuraniu! ele!ents have 'een produced
artificially.
25 2 Nuclear Transformations >25 2 Nuclear Transformations >
7/24/2019 Ch25 Lesson25_2
50/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
5 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
Which of the follo0in( al0a%s chan(es
0hen transmutation occurs?
*. )he nu!'er of electrons
+. )he !ass nu!'er
C. )he ato!ic nu!'er
&. )he nu!'er of neutrons
25 2 Nuclear Transformations >25 2 Nuclear Transformations >
7/24/2019 Ch25 Lesson25_2
51/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
51 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
Which of the follo0in( al0a%s chan(es
0hen transmutation occurs?
*. )he nu!'er of electrons
+. )he !ass nu!'er
C. The atomic num$er
&. )he nu!'er of neutrons
25 2 Nuclear Transformations >25 2 Nuclear Transformations > Jey ConceptsJey Concepts
7/24/2019 Ch25 Lesson25_2
52/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
52 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
Jey ConceptsJey Concepts
The neutron,to,'roton ratio in aradioisoto'e determines the t%'e of deca%
that occurs.
*fter each half,life) half of the ori(inalradioactie atoms hae deca%ed into atoms
of a ne0 element.
Transmutation can occur $% radioactiedeca%) or 0hen 'articles $om$ard the
nucleus of an atom.
25 2 Nuclear Transformations >25.2 Nuclear Transformations > Jey EuationJey Euation
7/24/2019 Ch25 Lesson25_2
53/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
5" Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
Jey EuationJey Euation
AG A1
2
n
25 2 Nuclear Transformations >25.2 Nuclear Transformations > Blossary )er!sBlossary )er!s
7/24/2019 Ch25 Lesson25_2
54/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations >
5$ Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
Blossary )er!sBlossary )er!s
0 nuclear force;an attractive force that acts'et(een allnuclear particles that are
e/tre!ely close together, li*e protons and
neutrons in a nucleus
0 $and of sta$ilit%;the location of sta'le nuclei
on a neutron8vs.8proton plot
0 'ositron;a particle (ith the !ass of anelectron 'ut a positive charge
25.2 Nuclear Transformations >25.2 Nuclear Transformations > Blossary )er!sBlossary )er!s
7/24/2019 Ch25 Lesson25_2
55/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations
55 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
Blossary )er!sBlossary )er!s
0 half,life;the ti!e reuired for one8half of thenuclei of a radioisotope sa!ple to decay to
products
0 transmutation;the conversion of an ato! ofone ele!ent to an ato! of another ele!ent
0 transuranium elements;any ele!ents in the
periodic ta'le (ith ato!ic nu!'er a'ove 72,the ato!ic nu!'er of uraniu!
25.2 Nuclear Transformations >25.2 Nuclear Transformations > +I
7/24/2019 Ch25 Lesson25_2
56/57
25.2 Nuclear Transformations >25.2 Nuclear Transformations
5 Copyright Pearson Education, Inc., or its affiliates. All Rights Reserved.
Electrons and the Structure of *toms
0 Dnsta'le ato!ic nuclei decay 'y e!itting
alpha or 'eta particles.
0 25.2 Nuclear Transformations >
7/24/2019 Ch25 Lesson25_2
57/57
25.2 Nuclear Transformations 25.2 Nuclear Transformations
EN& " 25.2EN& " 25.2