4 x 4
Lesson by
Sarah Kenyon

Time: 0.5 - 1 class periods
Prep Time: None
Materials: Extra articles for students who may have misplaced theirs.


In the previous lessons, students have considered first an article about new standards in groundwater arsenic levels and problems with compliance and the historical impact of arsenic. In this explain lesson, they are asked to generate 4 statements and 4 questions about arsenic based on these lessons. As the historical information is the most recent, and since the thrust of this learning cycle is to use arsenic as a focal point for discussions about groundwater, it will be useful to spend the first part of class revisiting the first article in light of what was learned in the explore lesson.

1) Students will generate four statements and four questions based on their current level of understanding of the article from the engage lesson
2) Students will evaluate the statements and questions that they have generated and those of their classmates and prioritize by narrowing 16+ to 2 representatives to share with the class
3) Students will individually respond to each statement and question.

National Science Education Standards
CONTENT STANDARD F: Science in Personal and Social Perspectives

  • Natural ecosystems provide an array of basic processes that affect humans. Those processes include maintenance of the quality of the atmosphere, generation of soils, control of the hydrologic cycle, disposal of wastes, and recycling of nutrients. Humans are changing many of these basic processes, and the changes may be detrimental to not only to the human populations, but also to the environment.
  • Many factors influence environmental quality. Factors that students might investigate include population growth, resource use, population distribution, overconsumption, the capacity of technology to solve problems, poverty, the role of economic, political, and religious views, and different ways humans view the earth.

Some hazards, such as earthquakes, volcanic eruptions, and severe weather, are rapid and spectacular. But there are slow and progressive changes that also result in problems for individuals and societies. For example, changes in stream channel positions, erosion of bridge foundations, sedimentation in lakes and harbors, coastal erosions, and the continuing erosion and wasting of soil and landscapes can all negatively affect society.

Teacher Background

Related and Resource Websites
Killer wallpaper: http://www.popularscience.co.uk/features/feat17.htm
Madness of King George (antimony, arsenic and porphyria): http://news.bbc.co.uk/1/hi/health/3889903.stm
The many faces of arsenic: http://news.bbc.co.uk/1/hi/health/medical_notes/459078.stm
US rice: http://www.nature.com/news/2005/050801/full/050801-5.html
Medical- current: http://phys4.harvard.edu/~wilson/arsenic/Image_Makeover1.htm
General: http://www.dartmouth.edu/~toxmetal/TXSHas.htm



Tell the students “When reading the article about water arsenic levels being too high, you generated a number of questions. Have any of your questions been answered? Do you consider yourselves experts yet? Are you more informed than you were before reading the article?”
To address these issues, you will ask them to take out the article that they read for the first lesson to use as a reference while they create 4 statements about arsenic that are relevant to the article. They will then create 4 questions that they feel still need to be answered. As a class, these questions and statements will be considered separately.

First statements will be delivered.
1) Each student will have their own four statements about arsenic.

2) Students will gather into their groups of 4 and consider all of their statements. They will be asked to pick two to share with the class.

3) Each group will present their two statements, which will be copied by each student and commented on/reacted to individually.

Then the questions will be considered. Again, students should be encouraged to put forward the questions that they find either a) most interesting to follow up on or b) something that is not clear to them from the previous day’s lesson.
4) Each student will have their own four questions about arsenic.

5) Students will remain in their groups of 4 and consider all of their questions. They will be asked to pick two to share with the class.

6) Each group will present their two questions, which will be copied by each student and commented on/reacted to individually.


Embedded Assessment

This is an opportunity for the teacher to assess where students are in their current understandings and what it is that they are attending to in the lessons. It is also a goal for the students to explain their current state of understanding about arsenic by using the statements to help explain the initial article.

PULSE is a project of the Community Outreach and Education Program of the Southwest Environmental Health Sciences Center and is funded by:

NIH/NCRR award #16260-01A1
The Community Outreach and Education Program is part of the Southwest Environmental Health Sciences Center: an NIEHS Award


Supported by NIEHS grant # ES06694

1996-2007, The University of Arizona
Last update: November 10, 2009
  Page Content: Rachel Hughes
Web Master: Travis Biazo