Science Practice: Constructing Explanations and Designing Solutions

The Empirical Formula of Magnesium Oxide Lab: A Successful Failure, Next Steps—and an Important Lesson

Michael Jansen reflects on a very common empirical formula lab that asks students to determine the empirical formula of MgxOy. He then explains how he continues to use it as a "successful failure", how he demonstrates an alternate procedure and leads his students to an important lesson.

Lesson to determine the relationships between acid strength, Ka, pH, Molarity, and percent ionization

After teaching the concepts and calculations for acid and base strength, concentration, percent ionization, and pH I noticed many of my students were struggling to make meaningful connections between these calculations.This lesson was created to strengthen the understanding of the relationships between these concepts and skills.

Exploration of Gas Laws Using Atomsmith Online

Using the online simulation tool (Atomsmith Classroom Online) and the ADI framework students investigate the properties of gases, along with two gas laws. An ADI "whiteboard discussion" helps in getting students to really process what the results of experiments mean to us as chemists - and how this leads to expanding our understanding of matter. This activity lends itself to an online classroom.

Color Changing Coke and Mentos

What's a better way to start the new school year than with some new experiments? Learn how to use a variety of color changing experiments to teach students about the Diet Coke and Mentos experiment, acids, bases, chemical and physical changes, and climate change.

Airbag challenge

In the “Airbag challenge” the students are tasked with developing a safe airbag for a car company. This formative assessment explores students’ thinking about the question “How can chemical changes be controlled?” The central concept in this challenge is the application is stoichiometry. Students are expected to use the numbers of moles of reactant consumed or product formed in a balanced chemical equation and to determine the change in the number of moles of any other reactant and product. Students need to use molar mass to convert mass of a reactant or product to moles for use in stoichiometric calculations or to convert moles from stoichiometric calculations to mass. Students use the ideal gas law equation to determine the numbers of moles in a sample of gas not at standard conditions.

Filling the Void: Options for Authentic Investigations Online

With the school year quickly approaching, science teachers will at some point need to decide the role of laboratory investigation within their new learning environment. To help this decision-making process, the author focuses on two available options that he believes have the greatest potential for offering a legitimate approach toward authentic investigations in a digital environment.