neutron, proton and electron

1. LESSON 1.1 NUCLEAR REACTION AND
ORIGIN OF ELEMENTS

2. HOW DID EVERYTHING
FORM?

3. • Everything around us is matter is composed of varying combination of
the 114 elements identified to be presented in the universe, including
earth.
• These elements are later found to be composed of atoms- the building
blocks of matter.
• How these elements formed and existed is explained by physics,
chemists, and astronomers on the basis of cosmology and the nuclear
reactions that occurred during the early existing of the universe.

4. INTRODUCTION TO NUCLEAR REACTIONS
• Nuclear reaction
• - are processes in which a nucleus either combines with another
nucleus (through nuclear fusion) or splits into smaller nuclei ( through
nuclear fission). These processes involve the emission of energetic
particles of an atom, a phenomenon known as radioactivity.
• The radioactive particles may be elements, electron, protons, and
neurons among others. Notice that each particle involve in a reaction
has a superscripts and a subscripts at the left-hand side symbol.
• These superscript and subscript are the particle’s atomic mass (A) and
atomic number (Z), respectively.

5. Radioactive particles
• Electron – negative charge
• Proton – positive charge
• Neutron – no charge
• Alpha particle (α ) – high-speed particle consisting of 2 protons and 2
neutrons
• Beta particle (β ) – high-speed electron
• Gamma ray (γ) – high-energy stream of photons
• Positron (e ) – positive-charge electron

6. The following are the most common types of nuclear reactions, along with
illustrative examples
Alpha decay: loss of an alpha particles ( 2
4
α )
Alpha decay of polonium -210 84
210
Po 82
206
𝑃𝑏 + 2
4
α
Beta decay: loss of beta particle (−1
0
β )
Beta decay of carbon -14 6
14
C 6
14
N + −1
0
β

7. Gamma radiation: emission of a gamma ray (0
0
γ)
gamma radiation in alpha decay of uranium -238
92
238
𝑈 90
234
𝑇ℎ + 2
4
𝛼 (alpha decay )
90
234
𝑇ℎ 90
234
𝑇ℎ + 0
0
𝛾 (gamma radiation )
Position emission: conversion of proton in a nucleus into neutron, along
with the release of a positron ( +1
0
𝑒 )
positron emission of oxygen -15 8
15
𝑂 7
15
𝑁 + +1
0
𝑒

8. Electron capture: drawing of an electron ( −1
0
𝑒 ) into an atom’s nucleus
electron capture of mercury -201 80
201
𝐻𝑔 + +1
0
𝑒 79
201
𝐴𝑢
Bombardment of alpha particle: addition of alpha particle
bombardment of beryllium with an alpha particle
4
9
𝐵𝑒 + 2
4
α 6
12
𝐶 + 0
1
𝑛
Other subatomic particles involved in nuclear reactions are the proton
(1
1
р ) and the neutron (0
1
𝑛 ).

10. • In each reaction, notice that the sum of the atomic masses of
the particles in the left-hand of the equation is equal to that
in the right-hand side. The same is true for the atomic
number. If a particle is missing in an equation, one can
easily identify it by arithmetically finding the atomic mass
and atomic number of the particle that will make the sum in
the two side of the equation equal. This process of
accounting for A and Z in the left and right sides of the
nuclear reaction equation is the key to balance the
equations.

11. Sample problem 1.1
• Which among the given particles will complete the nuclear reaction below ?
(0
1
𝑛, 2
4
α, −1
0
β, +1
0
𝑒)
88
226
𝑅𝑎 86
222
𝑅𝑛 + ______