Download Name Class Date QuickLab Using the Periodic Table Teacher Notes

Name ______________________________ Class ___________________ Date __________________
QuickLab
Using the Periodic Table
Teacher Notes
Instruct students to round the average atomic masses to a whole number to simplify
their calculations.
Carbon: atomic number = 6, average atomic mass = 12 amu
Iron: atomic number = 26, average atomic mass = 56 amu
Molybdenum: atomic number = 42, average atomic mass = 96 amu
Iodine: atomic number = 53, average atomic mass = 127 amu
SKILLS ACQUIRED
Collecting Data
Classifying
Identifying/Recognizing Patterns
MATERIALS

periodic table
PROCEDURE
1. Use the periodic table in your textbook to find the atomic numbers of the
following elements: carbon, iron, molybdenum, and iodine.
2. Determine the number of protons and electrons that are in each neutral atom of
the elements listed in step 1.
3. Find the average atomic masses of the elements listed in step 1.
ANALYSIS
1. Use the atomic number and average atomic mass of each element to estimate the
average number of neutrons in each atom of the elements listed in step 1 of this
activity.
Average number of neutrons: Carbon 12 − 6 = 6, Iron: 56 − 26 = 30,
Molybdenum: 96 − 42 = 54, Iodine: 127 − 53 = 74
2. Which element has the largest difference between its average number of neutrons
and the number of protons? Describe any trends that you observe.
iodine; The larger the atom, the larger the difference between the number of
protons and the number of neutrons.
© Houghton Mifflin Harcourt Publishing Company
Holt McDougal Environmental Science
i
Tools of Environmental Science
Name ______________________________ Class ___________________ Date __________________
QuickLab
Using the Periodic Table
MATERIALS

periodic table
PROCEDURE
1. Use the periodic table in your textbook to find the atomic numbers of the
following elements: carbon, iron, molybdenum, and iodine.
2. Determine the number of protons and electrons that are in each neutral atom of
the elements listed in step 1.
3. Find the average atomic masses of the elements listed in step 1.
ANALYSIS
1. Use the atomic number and average atomic mass of each element to estimate the
average number of neutrons in each atom of the elements listed in step 1 of this
activity.
2. Which element has the largest difference between its average number of neutrons
and the number of protons? Describe any trends that you observe.
© Houghton Mifflin Harcourt Publishing Company
Holt McDougal Environmental Science
1
Tools of Environmental Science