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Aliens Activity Mark as Favorite (81 Favorites)

ACTIVITY in Introduction, Periodic Table, Identifying an Unknown. Last updated March 25, 2020.


In this activity, students organize alien cards into groups and periods following trends, similar to how the periodic table is put together. The teacher can remove two cards from each student’s deck, and after they organize the cards the students can predict (draw) the missing aliens.

Grade Level

High school


By the end of this lesson, students should be able to

  • Understand how the periodic table is organized by organizing drawings of aliens.

Chemistry Topics

This lesson supports students’ understanding of

  • Periodic table
  • Trends of the periodic table


Teacher Preparation:

10 minutes


1 class period


For each group:

  • A stack of alien cards (see PowerPoint to create class sets—slides # 1&2 or 7&8)


  • No safety precautions need to be noted for this activity.

Teacher Notes

  • This activity is similar to what Mendeleev had to do to predict the yet undiscovered elements on the periodic table by using the properties of the elements around it.
  • The teacher could print the cards on colored card stock and laminate them. This helps students keep track of their cards.
  • The teacher removes two cards from each deck and has the students group the cards; look for pattern and finally draw the missing aliens.
  • The final table has five periods and eight groups (families). (Answer key is on PowerPoint slide #4)
  • The number of fingers increases as you move from left to right (this represents number of valence electrons)
  • The hair or number of legs or foot length increases as you move from top to bottom (this represents energy level of atoms)
  • An example of an incorrect alien table is included (PowerPoint slide #5)
  • A variation of this lesson would to have students predict aliens that would fit in period 6 and/or family 9.
  • Note that some of the aliens in columns 6, 7 and 8 of the cards only have one eye. This may be confusing for students (although intended to represent a division between metals and non-metals, as explained in the PPT). To remedy this, a teacher may wish to edit the alien sketches so that all of the aliens have 2 eyes. This might be helpful and eliminate any unintended confusion.