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Practice Assessment 3.1 – Atomic Theory
Learning Target 3.1: I can differentiate between ions and isotopes by explaining how the
properties of subatomic particles influence the stability and charge of an atom.
ATOMIC THEORY
1. Draw a Bohr model of a carbon atom, one with 6 neutrons and one with 8 neutrons.
2. What is the overall charge of the atoms you drew above?
3. What is the identity, mass (amu), and charge of an element with 29 protons, 34 neutrons, and 27
electrons?
4. What charge will a Sulfur atom have if it gains two electrons (16 protons and 18 electrons)?
5. What is the mass (amu) of a Uranium atom that has 92 protons, 92 electrons, and 146 neutrons?
Assessment 2.1- Gas Laws and KMT
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EMISSION SPECTRA
For the next two questions, look at the graph below. During the emission spectra lab, we calculated
the energy of each of the specific wavelengths of light emitted from the hydrogen atom.
6. What do the peaks represent?
7. What do the flat parts of the graph represent?
8. Emission spectra are evidence of the Bohr model because…
Assessment 3.1- Periodic Table and Atomic Theory
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QUANTUM MECHANICAL MODEL
9. Quantum mechanical model of the atom is a more accurate than the Bohr model of the atom
because…
10. In the space below, write the unabbreviated electron configurations of the following elements:
a. phosphorus
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b. fluorine
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c. carbon
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11. In the space below, write the abbreviated (noble gas) electron configurations of the
following elements:
a. magnesium
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b. silicon
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c. potassium
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12. Determine which elements are denoted by the following electron configurations:
a. 1s22s22p63s23p4
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b. 1s22s1
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c. [Ne] 3s23p5
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d. [Ne] 3s23p1
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Assessment 3.1- Periodic Table and Atomic Theory
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ISOTOPES AND NUCLEAR BAND OF STABILITY
In the nuclear stability simulation lab, we discovered that if we graphed number of neutrons vs. number
of protons for elements 1-10, we got the following data:
10. The overall pattern is a
linear pattern. What does the
slope of the best fit line
represent?
a.
The average atomic mass,
based on elements 1-10
b.
The average proton to
neutron ratio (p/n) for stable
atoms, based on elements 1-10
c.
The average neutron to
proton ration (n/p) for stable
atoms, based on elements 1-10
d.
The average neutron to
proton ration (n/p) for stable
atoms, based on all elements
11. We later read about the nuclear “band of stability” and saw that the overall pattern in the neutron
to proton ratio was not actually linear, but more exponential. What does this mean?
a. As there are more protons in the nucleus, the number of neutrons increases at the same
rate.
b. As there are more protons in the nucleus, there are less neutrons required.
c. As there are more protons in the nucleus, there are more neutrons required.
d. None of the above.
12. Which of the following statements about isotopes is incorrect?
a. Isotopes are versions of the same element
b. Isotopes are the same element with different masses
c. Some Isotopes can be radioactive, or unstable
d. Isotopes are the same element with different charges
13. The weighted atomic mass of Carbon is 12.011 amu. Carbon has two isotopes, carbon-12 and
carbon-14. Based on its weighted atomic mass, which of these two isotopes is the most abundant?
a. Carbon 12
b. Carbon 14
c. Both are present in the universe in equal amounts
d. None of the above
14. Why are atomic masses on the periodic table not whole numbers?
15. Magnesium has three naturally occurring isotopes. 78.7% of Mg atoms exist as Magnesium-24,
10.03% exist as Magnesium-25, and 11.17% exist as Magnesium 26. What is the average atomic
mass of Magnesium? Show your work in the space below.
Assessment 3.1- Periodic Table and Atomic Theory
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