Download Radioactive Reactions

Radioactive Reactions
• When an atom emits part of its NUCLEUS
(protons or neutrons) this is called radiation
• This happens because the nucleus is unstable.
• When an atom emits protons its identity
changes
• This can happen naturally (sun) or through
man made isotopes in a lab
Fission vs Fusion
• Fission: atomic nucleus splits into
parts (smaller). The particles leave
the nucleus causing energy to be
released. The atomic bomb and
nuclear reactors work by fission
• Fusion: atomic nucleus gets larger
because particles are coming into
the nucleus. In the Sun, hydrogen
nuclei fuse to make helium
• Both processes release massive
amounts of energy
CFU:
• What causes an atom to lose parts of its nucleus?
WB
• What is the significance of an atom losing protons
from its nucleus? TPS
• Name a difference between fission and fusion. WB
• Name a similarity between fission and fusion. WB
Nuclear force vs. Electrostatic Force
• Electromagnetic force: attraction between
charges
Positive attract to negative
Positive repel positive/negative repel
negative
• Protons and neutrons in the nucleus are held
together by nuclear forces. This is the “glue”
that prevents the protons from repelling one
another inside the nucleus
CST Release Question
The most abundant isotope of lead contains 82
protons and 124 neutrons packed closely together in
the nucleus. Why do the protons stay together in the
nucleus rather than fly apart?
A Electrons in neighboring atoms neutralize repulsive
forces between protons.
B Neutrons effectively block the protons and keep them
far apart to prevent repulsion.
C Electrostatic forces between neutrons and protons hold
the nucleus together.
D Nuclear forces overcome repulsive forces
between protons in the nucleus
CST Release Question
A 2-cm-thick piece of cardboard placed over a
radiation source would be most effective in
protecting against which type of radiation?
A alpha
B beta
C gamma
D x-ray
CFU
• Write one difference between nuclear force
and electrostatic force. WB
• Write one similarity between nuclear force
and electrostatic force. WB
Three types of radiation
• Alpha: weakest in strength. Cannot penetrate
cardboard 42He
0
• Beta: middle in strength - 1β
• Gamma: strongest in strength. Cannot penetrate
0
lead
0γ
Three Types of Radiation
• Alpha:
226
example: 88Ra
• Beta:
14
example: 6C
• Gamma:
example: 92 U
238
222
4 He
Rn
+
86
2
14
7N
+
0
-1β
4He + 2
Th
+
90
0
0
234
2
γ
Chemical Reaction
• All chemical reactions involve the movement of
valence electron in which chemical bonds are
formed
• Atoms want to have a stable outer energy level.
• Valence electrons move in a way that stabilizes
the atom outer energy level.
– Ionic bond: one atom gives the other receives
an valence electron
– Covalent bond: atoms share valence electrons
Nuclear Reactions
Atomic BOMB explosion
Chemical Reactions
Release/absorb
heat
Gas/bubbles
Sun: Fussion
Combustion
Precipitate
Chemical rxn vs. Radioactive rxn
• Energy release is much larger in nuclear reactions
than in chemical reactions.
• Nuclear reactions occur inside the nucleus with the
protons and/or neutrons
• Chemical reactions occur with the valence
electrons ONLY