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Pb206

Pb-206, or lead-206, is a stable isotope of the element lead (Pb) with 82 protons and 124 neutrons, giving it a mass number of 206. It is one of the four stable lead isotopes, the others being 204Pb, 207Pb, and 208Pb.

In nature, lead consists of all four stable isotopes, with approximate abundances around 204Pb ≈ 1.4%, 206Pb

Pb-206 is central to radiometric dating. Because 238U decays to 206Pb through a long decay series, the

Geochemically, Pb-206 behaves similarly to other lead isotopes in most processes, but its radiogenic origin means

≈
24%,
207Pb
≈
22%,
and
208Pb
≈
52%.
Pb-206
is
the
end
product
of
the
uranium-238
decay
chain
and
accumulates
in
minerals
as
radiogenic
lead
forms
over
geological
time.
amount
of
206Pb
increases
relative
to
the
remaining
uranium
as
time
passes.
Dating
methods
such
as
U-Pb
dating
use
the
ratios
206Pb/238U
and
207Pb/235U,
often
in
conjunction
with
the
stable
204Pb,
to
determine
the
age
of
rocks
and
minerals.
Pb-Pb
dating,
which
compares
206Pb
to
204Pb,
provides
information
about
initial
lead
composition
and
is
used
in
studying
planetary
and
solar
system
formation,
as
well
as
crustal
evolution
on
Earth.
its
proportion
relative
to
non-radiogenic
isotopes
records
geological
time.
The
isotope
is
stable
and
does
not
decay
further,
a
property
that
underpins
its
use
in
dating
systems
and
isotopic
tracing
of
geological
and
cosmochemical
processes.