1. Basic Atomic Structure
GPS Standards: SC1. Students will analyze the nature of matter and its classifications. a. Relate the role of nuclear fusion in producing essentially all elements heavier than hydrogen. SC3. Students will use the modern atomic theory to explain the characteristics of atoms. a. Discriminate between the size, charge, and position of protons, neutrons, and electrons in the atom. c. Explain the relationship of the proton number to the element’s identity.
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2. Name Location Mass proton neutron electron
I. Subatomic Particles
subatomic particle = a particle found inside the atom
nucleus = small, dense area in center of atom (p+ & n0 found here).
amu (atomic mass unit) = exactly 1/12 the mass of carbon-12 atom.
in a neutral atom, number of p+ = number of e- (# of n0 varies).
isotope = a variety of an atom that contains a different number of neutrons compared to others (still has same number of p+).
Name
Charge
Symbol
Location
Mass
proton +1 p+
in the nucleus
approx. 1 amu ( amu)
neutron n0
approx. 1 amu ( amu)
electron -1 e-
in orbitals
around nucleus
amu (negligible)

4. temps like this can be found in the center of stars, such as our Sun.
II. Nuclear Fusion
fusion = nuclear reaction involving 2 nuclei with low masses combining to form one nucleus of larger mass.
fusion can only take place at extremely high temps (millions of C), since the particles must be moving extremely fast to be able to react.
temps like this can be found in the center of stars, such as our Sun.
fusion reactors have not yet been built yet on Earth.
fusion reactions also release a tremendous amount of energy (E = mc2).

5. III. Describing the Atom
atomic symbol = a capital letter (or 1 capital, 1 lowercase) that symbolizes an element. Usually comes from current name, but can also originate from another language.
isotopic notation = way of writing the symbol to include the number of protons and neutrons (in nucleus).
Modern Name
Sym.
Older Name
silver Ag
argentum
gold Au
aurum
copper Cu
cuprum
iron Fe
ferrum
mercury Hg
hydragyrum
potassium K
kalium
sodium Na
natrium
lead Pb
plumbum
antimony Sb
stibium
tin Sn
stannum
tungsten W
wolfram
C = (just symbol for carbon)
carbon-12 = form of carbon with 12 total particles in the nucleus.
C-12 = another way to write #2 (using symbol instead of name)
12C = another way to write #2 (must be in upper-left-hand corner)

6. IV. Atom Numbers
atomic number = number of p+. Written in bottom left-hand corner of symbol. Identifies the element.
mass number = number of p+ & n0. Identifies the isotope. Written in top-left-hand corner.
charge = results from a gain or loss of electrons from the neutral amount (same as number of protons)
remember, electrons are negative, so….
positive charges result from an atom losing electrons
negative charges result from an atom gaining electrons
atomic mass (or weight) = weighted average of all the mass numbers of all the isotopes of an element Not written on symbol, but is found on PT. 14 6 C S -2
Carbon 6 C
12.01

7. Fill in the missing information using your periodic table:
Name of Isotope
Symbol
Atomic Number
Mass Number
Charge
# of Neutrons
# of Protons
# of Electrons
fluorine-___ 10 12 11
cobalt-60 +2 27
oxygen-17 8 -2
76 As __ 36

8. V. Nuclear Decay Equations
there are 2 types of decay processes: alpha (), and beta ().
alpha particle () = a radioactive particle consisting of 2 protons, 2 neutrons, and a charge of + 2.
the alpha particle is the most massive and most highly charged form of radiation.
because of this, they tend to lose energy quickly when they interact with matter (their high amount of charge reacts with other atoms and slows them down).
this makes them the least damaging radioactive particles (they can be blocked with a sheet of paper).

9. this makes them the least damaging radioactive particles (they can be blocked with a sheet of paper).
alpha particles can be damaging if they are ingested or inhaled into your body. Colliding with molecules like DNA and proteins can cause irreversible damage and can lead to birth defects and other illnesses.
when an isotope of an element undergoes alpha radiation, it turns into a new element through the process of transmutation.

10. when an isotope of an element undergoes alpha radiation, it turns into a new element through the process of transmutation.
the new element will have an atomic number 2 less than the original, and its mass number will decrease by 4.
the element’s symbol also changes to reflect the new atomic number.
beta particle () = a radioactive particle resulting from a neutron decaying into a proton and emitting an electron in the process, resulting in the addition of a proton.

11. beta particle () = a radioactive particle resulting from a neutron decaying into a proton and emitting an electron in the process, resulting in the addition of a proton.
when an isotope of an element undergoes beta decay, the new isotope’s atomic number will increase by 1. Its mass number remains the same.
the element’s symbol also changes to reflect the new atomic number.

12. beta particles are more damaging than alpha particles due to their smaller size.
the biological effects of beta radiation are similar, but more intense than alpha particles.
they can be blocked by a sheet of aluminum foil.
More Practice:
Fill in the decay equations below with the appropriate isotope or particle.

13. Write an alpha and beta decay equation for each isotope below.
More Practice:
Fill in the decay equations below with the appropriate isotope or particle.
Write an alpha and beta decay equation for each isotope below.