1. Hajer Mahmood
Science 10 Honors
Block C
Mr. Horton
May 12th, 2014
Half-life and Nuclear
Reactions

2. Half-life

3. Half-Life
Half-life is the time it took for
radioactivity of a specific isotope
to fall into half its original value.
Decay Curve
Half-life can be
demonstrated by a decay
curve. This is a curved line
that shows you the rate of
the decay.
Radiocarbon Dating
Radiocarbon dating is when you find the age of an element by the
amount of carbon-14 that is left inside of the element. Carbon-14 and
carbon-12 is in every plant or animal. They are equal when the organism
is alive, nut once it dies carbon-14 decrease which differs the ratio.
Common Isotope
Like everyone, including
The Hulk, we were
“made” by our parents.
Like isotopes there are
parent isotopes and
daughter isotopes. The
isotope goes through
radioactive decay (parent
isotope) which results in a
stable product of
radioactive decay
(daughter isotope)

4. https://www.youtube.com/watch?v=xhOtKurHayo

5. Show what you know
• Carbon-12 is what we use to determine the age
of an element? True or False
• The parent isotope produces an unstable
daughter isotope. True or False
• Half-life is:
I} The final moments of an element
II} The amount of time it took radioactivity to half
the original value of a specific isotope
III} Shown by a decay curve
a) I only b) I and III only c) II and III only

6. Nuclear Reactions

7. Nuclear Fission
This is the splitting of a large
nucleus into two smaller
nuclei, subatomic particles
and energy. Nuclear Fission
is the nuclear energy that is
used for power generation,
because fission gives off a
lot of energy.
Heavier nuclei=more
unstable, because of the
repulsive forces between
protons. To fix this problem
atoms who have heavy
nuclei can split into atoms
with lighter nuclei.
Nuclear Fusion
This is when two low
mass nuclei join
together to make a
bigger nucleus. This
happens in the core
of Sun. (high
pressure and high
temperate force
isotopes of hydrogen
to collide with great
force)

8. https://www.youtube.com/watch?v=FU6y1XIADdg

9. Nuclear Reaction
When an atom’s nucleus
changes either by gaining or
releasing particles or energy it is
a nuclear reaction. It can release
all three types of subatomic
particles, and also gamma rays.
Small change in mass=large
change in energy
Nuclear reaction happens
when bombarding a
nucleus with alpha
particles, beta particles and
gamma rays
Induced means when a
scientist makes a nucleus
unstable and undergo a
nuclear reaction.
Subatomic Particle
Symbols
(protons) (neutrons) (electrons)
Rules for Writing Nuclear
Equations
• The sum of the mass numbers
on each side of the equation
stays
• The sum of charges (shown by
atomic numbers) on each side of
the equation stays the same

10. Chain Reactions
It is the ongoing process in where one
reaction initiates the next reaction.
Figure 7.21). The amount of fissions as
well as the energy released will increase
largely and it can cause a violent nuclear
explosion.

11. Show what you know
• Name at least two differences between
nuclear fission and nuclear fusion.