In the simplest terms, an unstable nucleus of an atom breaks apart
into smaller parts.
Iodine-131 produces (loses) a
beta particle to produce xenon-131.
Transmutation-When an element turns into a different
element. This occurs when the number of protons changes.
Transmutation- Without the presence of an another entity,
the number of protons change. In simpler terms there is only one
Transmutation- A change in the number of protons caused
by another entity. So there are two reactants.
Writing Alpha Decay Expression
In alpha decay, an atom will produce an alpha
particle. When you write a nuclear equation, mass must
be conserved. The total mass on the left of the arrow,
and the total mass on the right of the arrow are
equal. In addition to mass being conserved, the total
number of protons on the left must equal the total number of
protons on the right.
Radium-222 undergoes alpha decay to produce
The total mass on the left is 222 and the total mass on
the right is 222 (4 + 218). The total number of
protons on the left is 88 and the total number of protons on
the right is 88 (2 + 86).
During alpha decay, the mass of the parent atom decreases
by 4 and the atomic number decreases by 2.
Writing Beta Decay Expression
In beta decay, an atom will produce a beta particle
(electron). Please keep in mind that this is different
from losing an electron to become an ion. In beta
decay a neutron becomes a proton by producing an
electron. When an atom loses an electron to become an
ion, the atom is simply losing an electron from outside the
nucleus. Thorium-234 will become protactinium-234 by
producing a beta particle.
During beta decay, the mass does not change but the
atomic number increases by 1.
Electromagnetic radiation, with a short wavelength, and very
high energy. Produced by the rearrangement of particles in
the nucleus or certain electron transitions. Very
penetrating, very dangerous.
Writing Positron Decay Expressions
In positron decay, an atom will produce a particle that
has the same mass as an electron but with a positive
charge. Sodium-22 will undergo positron emission to
During positron decay, the mass does not change but the
atomic number decreases by 1.
Note-These natural transmutations only have 1 reactant.
--> 4, all
the other reactions have 2 reactants
65-->Pb-206 has a stable
nucleus and is not radioactive
Radioactive Decay Series of U-238 to Pb-206
decays to Pb-206 through a series of natural transmutations
until it reaches lead-206.
ratio of U-238 to the amount of Pb-206 in a geological sample
can be used to calculate the age of the rocks
table below show pne of the possible ways that U-238 can decay