Atomic Trends
Chemistry Laboratory
Honors Chemistry (820), 2017-18


Last update: Tuesday, November 11, 2008 3:01 PM


The purpose of this activity is arrange elements into a logical sequence that exhibits periodic trends that are based on chemical and physical properties of the elements.


Dimitri Mendeleev published a periodic table of the known elements in 1869. He organized the elements according to a number of chemical and physical properties into rows and columns where the elements in each column had similar chemical properties, and showed a progression in physical properties. His periodic table showed great similarity to the periodic table we use today.


Assemble the following tools prior to starting the activity:

Safety and Waste Management

A large surface area is best for this activity, so it is convenient to work on the laboratory benches. Be certain to clean your workspace carefully, before starting. Safety eyewear is not required for this activity. Scissors can cut skin as well as paper, so be careful.

Clean up all scraps of paper, and return all tools and materials to their assigned locations.


Patterns in the Properties of Elements
  1. Examine the page containing 20 element data cards. Each card lists some chemical and physical properties of an element.
  2. Carefully cut out each card.
  3. Arrange the cards in order of atomic weight.
  4. Try sorting the cards into several different groups. Each group should include elements with similar chemical or physical properties. You may need to try several different sorting methods before you find one that makes sense to you.
  5. Examine the cards in your groups for any patterns. Arrange the cards within each group in a logical sequence. This may also require several different arrangements until you find one that makes sense.
  6. Take a look at how the chemical and physical properties differ from group to group. Use these differences to arrange the groups into a logical sequence.
  7. Select the most reasonable and useful patterns within and among the groups to arrange the cards into a table. Your result should contain rows and columns where each column contains one of your groups of cards, and the progression of chemical properties across each row makes logical sense. When you are satisfied with your arrangement, glue or tape the cards to a sheet of paper to preserve the pattern.
  8. Once the cards are fixed in place, number each element from 1 to 20 starting with the lowest mass element, then working across the first row, then wrap around to the second row, etc.
Trends in Chemical Properties
  1. Entitle one of the sheets of graph paper, "Trends in Chemical Properties."
  2. Label the x-axis "Atomic Number of E." Scale your labels to the number of elements you need to display.
  3. Label the y-axis "Oxygen Atoms per Atom of E." Scale the axis to accommodate the range of values you will have to display.
  4. Create a bar graph by plotting the oxide data from the elements according to the atomic number order you established after fixing the cards to the paper.
Trends in Physical Properties
  1. Entitle the other sheet of graph paper, "Trends in Physical Properties."
  2. Label the x-axis "Atomic Number." Scale your labels to the number of elements you need to display.
  3. Label the y-axis "Boiling Point (K)." Scale the axis to accommodate the range of temperature you will have to display, however, exclude element 6 as the boiling point of this element is substantially greater than the rest of the elements.
  4. Create a bar graph using the boiling point data from the element cards.

Post-activity Questions

  1. Does either of your bar graphs reveal a repeating, or cyclic, pattern? Describe any patterns you observe.
  2. Are these graphs consistent with the patterns you found while grouping the elements? Explain.
  3. Based on the two graphs you created, why is the chemist's organization of the elements called the periodic table?
  4. Where are the elements with the highest oxide numbers located on the periodic table?
  5. Where are the elements with the highest boiling point located on the periodic table?
  6. Explain any trends you noticed in Q4 and Q5.
  7. Predict which elements should have the lowest boiling point: Se, Br, or Kr. Use evidence from your graphs to explain how you decided.
  8. Using your graphs, predict the pattern in boiling points and oxide numbers for elements 31 through 36.

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