Download Name:

.Mr.
Shields
Learning Objectives - Unit 1
Atomic Structure & Isotopes
Regents Chemistry
 Review and understand how to use Sig. Figs. in mathematical problems
 Know the element names/symbols you were assigned to learn
 Know that Democritus first introduced atomic theory over 2000 years ago
- Know that Aristotle’s hypothesis that everything is made of the 4 elements earth, wind, fire, water
prevailed
 Know what the two main arguments were against Democritus’ atomic theory
 List the 5 postulates (ideas) of Dalton’s reintroduction of atomic theory in early 1800’s.
 Know which two of Dalton’s statements are not considered correct today and why.
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Thomson discovered the electron in 1897. Be able to fully describe his “Plum Pudding” model of the atom.
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Describe the experiment in which Rutherford directed a radioactive beam through an electric field. Describe the
three particles he discovered including their charge. Know which electrode each particle was attracted to.
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Be able to describe in detail Rutherford’s Backscattering (gold foil) experiment
o Based on his experiment be able to discuss Rutherford’s conclusion regarding the structure of the atom
o Know what the problem was with Rutherford’s model of the atom?
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Be able to describe the Bohr model of the atom and be able to explain why it fixed the problem with
Rutherford’s model.
o Know that Bohr’s electrons only existed in specific Energy Levels called orbits
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Be able to compare and contrast the Thomson, Rutherford and Bohr models of the atom
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Know that particles in the nucleus, protons and neutrons, are collectively called nucleons.
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Know it was Rutherford who discovered the proton and Chadwick who discovered the neutron
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Be able to provide charge and mass (in AMU’s) for protons, neutrons, electrons and alpha particles.
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Be able to determine the number of protons, neutrons & electrons in an atom when given atomic # & mass #.
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Know that C-12 is the standard used to determine the atomic mass of all other atoms in AMU’s
o Know that the Mass of C-12 in AMU’s is exactly 12
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Know the definition of an Ion
o Know that anions are negative (A-)/ Cations are positive (C+)
o Charge consists of both sign & number and is specified in the upper right next to an elements Symbol
o Be able to calculate the charge on an atom when given the number of electrons and atomic number
o Be able to calculate the number of electrons an ion has for a given charge.
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Be able to provide the definition of an isotope

Given several atoms be able to recognize which are isotopes of one another and which are not based on atomic
# and mass number.
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Know the names of the three isotopes of Hydrogen, their mass numbers the number of neutrons each has.
Be able to provide the notation for isotopes of an element (e.g., Carbon-14 or 126C, C-14)
Be able to calculate the average atomic mass of an element, given the isotopic abundances & atomic masses.
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