electron capture occur when
an inner electron is captured by a nucleus , a proton decays in a neuton and the
atomic number decreases while the mass number remain constant.
 in a positron decay,  a proton decays in a positron and a neutron,
the atomic number decreases by one. while the mass number remain constant.
  They both have same effect
on the  atomic number and mass number of
atom, they only difference is that they occur in different ways, 
Example of electron capture
19682Pb+0-1e
→ 19681Tl
 Example of positron decay
5025Mn→ 5024Cr
+0+1e
 differences
As we can see the electron capture  dos involve emission of particles  while positron involves  emission of positron
 Electron capture is an
internal affair while positron is not.
what is the daughter nucleus produced when 123in undergoes electron capture?
When indium -123 undergo  an
electron capture, one of its proton decay into a neutron, in the process an
inner electron is captured by the nucleus, and this result to a decreases in
atomic number by one while the mass number remain unchanged. The atom that fit
the above description is  cadmium-123.
 Let us write the nuclear
decay equation for the above reaction.
12349 In +0-1e
→  12348Cd
 From the above reaction we can  balance it , to see if we are right or wrong.
to balance a nuclear
equation we have to ensure that the total sum of the supercritp on both side
must be equal as well the total sum of the subscript,
 for the superscript
 we have
123 + → 0 123
what is the daughter nucleus produced when 63zn undergoes electron capture?
6330 Zn +0-1e
→  6329Cd
→
→
what is the daughter nucleus produced when 167tm undergoes electron capture?
16769 Tm +0-1e
→ 16768Er
Let us balance the above equation to see if  we are right or wrong.
To balance a nuclear decay equation, we start by checking the
atomic number of the nuclide and mass number, or simply the subscript and the
super superscript.
 For the superscript, we
have;
167 +0 → 167
And for the subscript, we have
69+(-1) → 68
 The above equation is
therefore balanced.
what is the daughter nucleus produced when 195au undergoes electron capture?
 When  gold with a mass number of 195 and
atomic number of 79 undergo electron capture, one of its inner electron is
absorb by the nucleus,  the number of
protons in gold decreases by one while the total number of nucleons remain
unchanged.
 The  daughter nuclide formed will have an atomic
number of 78 and a mass number of 195, the atom that fit the above description
is platinum-195.
 Let us write the decay equation now.
19579Au +0-1e
→ 19578Pt
what is the daughter nucleus produced when 83 sr undergoes positron emission
when strontium-83 with atomic number 38 undergo an
electron capture, the atomic number of the daughter nuclide formed will be 37
and the mass number will be 83.
 Let
us put down the decay equation first
8338Au → 8337Pt
+0+1e
→
→
what is the daughter nucleus nuclide produced when 50mn undergoes positron emission
 when manganese
undergo a positron decay, one of its proton decays into an a positron, a
neutron and an electron neutrino .  the
atomic  number of the daughter nuclide
formed decreases by one while the mass number remain the same.
  Thee
daughter nuclide that will be formed will have atomic number of  24 and mass number of 50. The atom that will fit
the above description is chromium-50
 Let
us write the above in nuclear equation
5025Mn→ 5024Cr +0+1e
what is the daughter nucleus produced when 196pb undergoes electron capture?
 When lead undergo
an electron capture, the atomic number decreases by one while the atomic mass
remain unchanged. The daughter nuclide formed will have an atomic number of 81
and a mass number of 196
 We can write this in a nuclear equation
19682Pb+0-1e
→ 19681Tl
what nuclide is formed when 90sr undergoes β decay?
 When strontium undergo a beta decay, the
atomic number of the new atom increases by one while the mass number remain the
same, during a beta decay a neutron decays into a proton, an electron and an
electron antineutrino.
 The daughter nuclide formed will then have an
atomic number of 51 and a mass number of 90, the nuclide that will satisfied
the above condition is antimony-90
9050Sr→ 9051Tl
+0-1e
We can balance the above equation to see if we are right or wrong.
 To balance a nuclear equation
the law of conservation of mass requires that total mass and charge on the
reactant side must be equal to the  total
mass on the product side and the total charge on the product side must be equal
to  the total charge on the product side.
 In order word, the sum of
the mass numbers on the reactant side must be equal to the sum of the mass
number on the product side and the sum nuclear charge on the product side must
be equal to the sum of the nuclear charge on the product side.
 Therefore for the left hand
side, we have a total of  90 on the left
hand side and a total of 90+0 on the right hand side.  And for the nuclear charge we have a total of
50 on the reactant side and a total of 51+(-1) on the product side.
calculate the mass defect for u-238 which has a mass of 238.050784 amu.
 mass defect is the difference between the
calculated mass an the measured mass, the calculated mass is obtained by  multiplying the total number of nucleons  with their respective masses. 
 For the above example, the measured mass
is  238.050784 amu. While the calculated
mass can be calculated as 
The total number of nucleon in
uranium is 238,
 The number of protons is 92
The number of neutrons is 238-92=
146
 The mass of a proton is 1.0072766 a.m.u
The mass of neutron is 1.008701
amu
Mass defects  is 239.9397932-238.050784
 1.8890092 amu
calculate the mass defect for u-235 which has a mass of 235.04392 amu.
mass defect is the difference
between the calculated mass an the measured mass, the calculated mass is
obtained by  multiplying the total number
of nucleons  with their respective
masses. 
 For the above example, the measured mass
is  235.04392amu. While the calculated
mass can be calculated as 
The total number of nucleon in
uranium is 238,
 The number of protons is 92
The number of neutrons is 235-92=
143
 The mass of a proton is 1.0072766 a.m.u
The mass of neutron is 1.008701
amu
 
 
Mass defects  is 236.9136902-235.04392amu
1.8697702amu
write a nuclear reaction for the neutron-induced fission of u−235 to produce te−137 and zr−97.
 Let us 
write  the decay equation, 
10 n +
23592U→  13752Te +9740Zr  +2 10 n
The above equation is for nuclear fission decay equation, 
 Uranium-235 is bombarded with a neutron
and tellurium-137 and zirconium-97 is formed.
 Let us balance the above
equation to see if we are right or wrong,
  The above equation is for
nuclear fission decay equation, 
 For the super script, we
have, 
1+235 → 97 +137+ 2= 236
And for the subscript
0+92 = 52+40+0=92
 Therefore, the equation is
balanced.
 
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