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Why Is The Sea Salty? Lesson Plan

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Lesson Plan #:AELP-GLG003
Submitted by: Pam Hansen and Christy Bingham Cleveland Elementary School, Cleveland, UT
Endorsed by: These lesson plans are the result of the work of the teachers who have attended the Columbia Education Center’s Summer Workshop. CEC is a consortium of teacher from 14 western states dedicated to improving the quality of education in the rural, western, United States, and particularly the quality of math and science Education. CEC uses Big Sky Telegraph as the hub of their telecommunications network that allows the participating teachers to stay in contact with their trainers and peers that they have met at the Workshops.
Date: May 1994

Grade Level(s): Kindergarten, 1, 2, 3


  • Science/Geology
  • Science/Oceanography

OVERVIEW: In preparing for an ocean unit, do a ‘K-W-L’ organizer. ‘K’ is for what we know about the ocean. ‘W’ is for what we want to learn about the ocean. ‘L’ is for what we have learned about the ocean. The following lesson was developed because the students wanted to know why the ocean is salty. PURPOSE: For students to observe how salt concentration increases in water. Also, how the salt remains after the water evaporates.


The student will be able to explain why the sea is salty.


Rock salt, water, containers, strainers. Book: Oceans, Instructional Fair, Inc., Grand Rapids, MI


  • Students pour water over the rock salt which is contained in a strainer. The water plus dissolved salt will be collected in a plastic cup. Students will taste the water sample.
  • Students will allow the water to evaporate, observing that the salt remains.
  • The above procedure is repeated over a 3 or 4 day period. The students will observe that the salt increases each time new water is added.
  • TYING IT ALL TOGETHER: Students will do a Saltwater Painting to once again observe the evaporation process. Mix warm water, salt, and food coloring. Paint pictures with the mixture on white paper. Let dry. The water evaporates, but the salt remains, creating beautiful pictures.