Investigation One introduces students to the science of chemistry as the study of the properties of matter. Through observation and experimentation, students will learn to differentiate between qualitative and quantitative properties. Students will discover that the pan balance can be used to compare the amount of matter in different samples, but that a new Procedural Tool, the triple beam balance, is preferred for determining the exact amount of matter in a sample and for quantifying differences in the amount of matter between samples.

In Investigation Two, students continue their study of mass and properties of matter with experiments designed to demonstrate that mass is dependent upon sample size. Students will also learn how to account for the mass of a container when weighing substances. Students will discover through summarization of their results that changing a quantitative property such as mass has no effect on many of the qualitative properties of either solids or liquids. 

Investigation Three introduces students to interactions between solids and liquids and between liquids. Through experimentation and observation, students will explore the fundamentals of mixtures and solutions, and learn to identify the components of a solution based on their behavior in relation to each other. Students will also learn to recognize the similarities and differences between solubility and miscibility. 

Investigation Four provides students an opportunity to expand their study of matter by exploring the differences between physical and chemical change. Students will learn that there are ten common signs of chemical change and that these signs are often present during physical changes. Students will observe physical and chemical examples of three of the common signs, and through comparison and discussion, examine the process by which scientists determine whether such signs are the result of physical or chemical changes in real-world applications. 

Investigation Five presents students with an introduction to pH, a method of classifying matter based on its acidity or basicity. Students will learn that pH can be quantified using a pH scale. Students will use the pH scale to explore and compare the relative acidity or basicity of a variety of common substances. Students will also practice making solutions and use these solutions to explore the effects of decreasing amounts of baking soda and increasing amounts of water on pH. An optional extension is provided to expand this exploration to an acidic compound, white vinegar. 

Investigation Six consists of a Performance Assessment designed to evaluate students’ understanding of the science concepts addressed in the first five Investigations of the CELL. During this exploration, students will use the knowledge gained about the properties of matter, solutions, physical and chemical changes, and pH to identify which of four mixtures is made from two unknown substances.