Physical science

1. Nuclear Reaction

2. Nuclear Reaction

3. Common Types of Nuclear Reaction

4. Common Types of Nuclear Reaction

5. Let’s practice!
Direction: Complete the following nuclear reactions in order to balance the equation.
1. 91
231
𝑃𝑎 → _________ + 2
4
𝛼
2. ______________→ 18
40
𝐴𝑟 + 2
4
𝛼
3. 47
107
𝐴𝑔 → 46
107
𝑃𝑑 + __________
4. 73
180
𝑇𝑎 + −1
0
𝑒 → _________
5. 37
86
𝑅𝑏 → _________ + 1
1
𝑝
6. 78
195
𝑃𝑡 → _________ + 0
1
𝑛
7. ______________→ 56
137
𝐵𝑎 + 0
0
𝛾
8. ______________→ 67
165
𝐴𝑟 + −1
0
𝛽
9. 71
175
𝐿𝑢 + _________ → 70
175
𝑌𝑏
10. 15
31
𝑃 + 2
4
𝛼 → _________ + 0
1
𝑛

6. Nuclear
Reactions during
Big Bang,
Stellar and
Supernova
Nucleosynthesis

7. BIG BANG
● Big Bang Theory
● Evidence first expressed in the early 1900s by EDWIN
HUBBLE where he believes that the universe is expanding.
● Big bang theory postulates is aproximately 14 billion years
ago
● First 3 minutes after the explosion, subatomic
particles such as PROTONS, NEUTRONS, and
ELECTRONS were formed.

8. Big bang Nucleosynthesis Reactions
1
1
𝑝 + 0
1
𝑛 → 1
2
𝐻 + 0
0
𝛾
1
2
𝐻 + 1
1
𝑝 → 2
3
𝐻𝑒 + 0
0
𝛾
1
2
𝐻 + 1
2
𝐻 → 1
3
𝐻 + 1
1
𝑝
1
2
𝐻 + 1
2
𝐻 → 2
3
𝐻𝑒 + 0
1
𝑛
1
3
𝐻 + 1
2
𝐻 → 2
4
𝐻𝑒 + 0
1
𝑛
2
3
𝐻𝑒 + 1
2
𝐻 → 2
4
𝐻𝑒 + 1
1
𝑝
Hydrogen
and
Helium

9. STELLAR FORMATION &
EVOLUTION
 Hydrogen and helium gases condensed to from
stars, including sun.
 During stellar evolution, nuclear reactions
continued, which produced elements heavier than
lithium ( 3𝐿𝑖 to 26𝐹𝑒) .
 Light elements combined to form atoms of carbon,
neon, oxygen, silicon, and iron.

10. RED STAR

11. Stellar Nucleosynthesis Reactions
Reactions in the Hydrogen Fusion Shell:
1
1
𝐻 + 1
1
𝐻 → 1
2
𝐻 + +1
0
𝑒
1
2
𝐻 + 1
1
𝐻 → 2
3
𝐻𝑒 + 0
0
𝛾
2
3
𝐻𝑒 + 2
3
𝐻𝑒 → 2
4
𝐻𝑒 + 1
1
𝐻 + 1
1
𝐻
Reactions in the Helium Fusion Shell:
2
4
𝐻𝑒 + 2
4
𝐻𝑒 → 4
8
𝐵𝑒
2
8
𝐵𝑒 + 2
4
𝐻𝑒 → 6
12
𝐶
Reactions in the Carbon Fusion Shell:
6
12
𝐶 + 6
12
𝐶 → 10
20
𝑁𝑒 + 2
4
𝐻𝑒
6
12
𝐶 + 6
12
𝐶 → 11
23
𝑁𝑎 + 1
2
𝐻
Reactions in the Neon Fusion Shell:
10
20
𝑁𝑒 + 0
0
𝛾 → 8
16
𝑂 + 2
4
𝐻𝑒
10
20
𝑁 + 2
4
𝐻𝑒 → 12
24
𝑀𝑔 + 0
0
𝛾
Reactions in the Oxygen Fusion Shell:
8
16
𝑂 + 8
16
𝑂 → 14
28
𝑆𝑖 + 2
4
𝐻𝑒
Reactions in the Silicon Fusion Shell:
• The fusion of 14
28
𝑆𝑖 produce
radioactive 28
56
𝑁𝑖, which then
decayed to 26
55
𝐹𝑒.

12. Stellar Explosion/Supernova
Nucleosynthesis
● Supernova is a violent explosion of star where it released a
huge amount of nuclear energy and produced, through neutron
capture and radioactive decay, where other elements heavier
than iron is formed.
S-process or slow process
28
62
𝑁𝑖 + 0
1
𝑛 → 28
63
𝑁𝑖 neutron capture
28
63
𝑁𝑖 → 29
63
𝐶𝑢 + −1
0
𝛽 beta decay of unstable 28
63
𝑁𝑖
29
63
𝐶𝑢 + 0
1
𝑛 → 29
64
𝐶𝑢 neutron capture
29
64
𝐶𝑢 + 30
64
𝑍𝑛 + −1
0
𝛽 beta decay of unstable 29
64
𝐶𝑢
Elements formed: nickel (Ni), copper (Cu), zinc (Zn)

13. Stellar Explosion/Supernova
Nucleosynthesis
R-process or rapid process
26
56
𝐹𝑒 + 0
1
𝑛 → 26
57
𝐹𝑒 series of neutron capture of Fe
26
57
𝐹𝑒 + 0
1
𝑛 → 26
58
𝐹𝑒 (also written as 26
56
𝐹𝑒 + 30
1
𝑛 → 26
59
𝐹𝑒)
26
58
𝐹𝑒 + 0
1
𝑛 → 26
59
𝐹𝑒
26
59
𝐹𝑒 → 27
59
𝐶𝑜 + −1
0
𝛽 beta decay of unstable 26
59
𝐹𝑒
Elements formed: cobalt (Co)

14. Atoms from the
Eyes of
Philosophers
and Scientists

15. Timeline on the Brief History on Matter and
Atoms
YEAR EVENT
450 BC
Empedocles asserted that all things are composed of four primal
elements: earth, air, fire, and water.
400 BC
Democritus proposed that all mater is made up of very small particles
called atoms, which cannot be divided into smaller pieces.
380-320
BC
Aristotle proposed that all mater was continuous and can be further
divided infinity into smaller pieces.
1799 Joseph Proust proposed that law of definite proportions.
1808
John Dalton formulated the atomic theory and proposed the law of
multiple proportions.

16. YEAR EVENT
1869
Dmitry Mendeleev arranged the known elements in a periodic table based
on their atomic mass.
1890s
Antoine Becquerel and Marie Curie observed that radioactivity causes
some atoms to break down spontaneously.
1895 Wilhelm Röntgen discovered X-rays.
1897 Joseph John Thompson discovered electrons.
1904
Joseph John Thompson suggested the plum pudding model of the atom
(negative electrons dispersed in a positive structure).
1908 - 1917
Robert Millikan found that the charge of an electron is equal to −1.6022 ×
10−19
𝐶

17. YEAR EVENT
1910 - 1911 Ernest Rutherford observed that atoms are mostly empty space.
1913
Niels Bohr proposed an atomic model that shows electrons move in
concentric orbits around nucleus.
Henry Gwyn Jeffreys Moseley used X-ray spectra to study atomic
structure.
1919 Ernest Rutherford discovered protons.
1932 Ernest Rutherford discovered neutrons.

18. John Dalton
Dalton’s Atomic Theory
1. Elements are made up of small indivisible particles
called atoms.
2. In any given pure element, the mass and other
properties of all the atoms are the same. Atoms of
different elements differ in mass and other properties.
3. Compounds are composed of atoms of more than
one element. The constituent atoms in a given
compounds are present in a consistent or constant
whole number ratio.
4. In a chemical reaction, atoms are neither created
nor destroyed. They simply combine, separate, or
rearrange.

19. Structure of an Atom
Neutrons
• It is a neutral charged particle in the
nucleus.
• Magnitude charge: 0
• Weight: 1.67262 × 10−24
grams
Protons
• It is a positively charged particle in
the nucleus.
• Magnitude charge: 1.6022 × 10−19
𝐶
• Weight: 1.67262 × 10−24
grams
Electrons
• It is a negative charged particle
surrounding the nucleus.
• Magnitude charge: 0
• Weight: 1.67262 × 10−24
grams

20. Atom Number and Atomic Mass
Atomic mass = number of protons + number of neutrons
= atomic number + number of neutrons
𝑍
𝐴
𝑋 element
atomic mass
atomic number

21. Isotopes
Z = 1
A = 1
Z = 1
A = 2
Z = 1
A = 3

22. Ions
An ion is an atom or group
of atoms that has an
electric charge.
A positively charged ion is
called cation.
A negatively charged ion is
called anion.
𝑍
𝐴
𝑋
𝑞
The charge of an ion can be computed using
these formula:
𝑞 = 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑝𝑟𝑜𝑡𝑜𝑛𝑠 − 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑒𝑙𝑒𝑐𝑡𝑟𝑜𝑛𝑠