Astronomy – Practice in Chemistry

 

This is a portfolio entry.  Provide answers to the following questions on separate sheets of paper.  Your responses should be neat and thoroughly detailed.  For questions requiring mathematical operations, show all work in a neat and methodical fashion.  Be sure to include all steps.

 

  1. The most common form of iron has 26 protons and 30 neutrons in its nucleus.  State its atomic number, atomic mass, and number of electrons if it’s electrically neutral.  How did you determine these responses?
  2. Consider the following three atoms.  Atom 1 has 7 protons and 8 neutrons, atom 2 has 8 protons and 7 neutrons, atom three has 8 protons and 8 neutrons.  Which two are isotopes of the same element?
  3. Oxygen has an atomic number of 8.  How many times must an oxygen atom be ionized to create an O+5 ion?  How many electrons are in an O+5 ion?
  4. Consider fluorine atom with 9 protons and 10 neutrons.  What are the atomic numbers and atomic mass of this fluorine? Suppose we could add a proton to this fluorine nucleus.  Would the result still be fluorine?  Explain.  What if we added a neutron to the fluorine nucleus?
  5. The most common isotope of gold has an atomic number of 79 and an atomic mass of 197.  How many protons and neutrons does the gold nucleus have?  If it is electrically neutral, how many electrons does it have?
  6. The most common isotope of uranium is 238U.  The form used in bombs and power plants is  235U.  Given that Uranium has an atomic number of 92, how many neutrons are in each of these two isotopes of uranium?
  7. Draw a model of the iron in #1 and  the O+5 ion in #3.

 

For item 8, calculate the average density of the object in grams per cubic centimeter.

  1. A rock with volume 15 cm3 and mass 60 kg.