This five-lesson unit was designed to introduce elementary students to the basic chemistry behind making playdough as they take on the role of a chemical engineer and endeavor to develop a process (or recipe) for making playdough. In addition, it will inject a fundamental knowledge of chemistry, and students will use the basis of this knowledge to improve consistency in producing high-quality playdough that is comparable to retail brand “Play-Doh” in texture, elasticity, and pliability. Along the way, students will learn the role of each ingredient and the reasoning behind each step of the process (mixing, kneading, and applying heat). There will also be room for experimentation as students explore the role of added ingredients and/or vary the preparation and cooking processes. Students will record their measured ingredients and procedures used for each batch of playdough in a chemical engineering journal and present their best final product to the class. The unit promotes an introduction to chemistry, engineering, and using an organized method to record notes and observations. Not only that, but making playdough is a lot of fun! Fair warning – students will be excited, and some results may come out sticky and messy! The unit is designed to take five one-hour long class sessions but can be extended or shortened at the discretion of the teacher.

The purpose of this unit is to make EM waves of different wavelengths apparent in students’ everyday lives. This will be accomplished by using devices that students are already familiar with and most likely take for granted ­­–microwave and conventional ovens. Students come into the classroom with the understanding that the microwave oven makes their food hot but without knowing why or how this happens at a molecular level. This unit will give the students real-world context for applications of microwaves and infrared waves.

Understanding wave properties and EM waves is relevant to students because EM waves are used for many purposes and surround us every day. These EM waves are used for technology. There are valid health and safety concerns with exposure to some higher frequency waves, such as ultraviolet radiation, x-rays, and gamma rays. This unit will explore why the microwaves in the microwave oven and infrared radiation from the conventional oven do not have the same safety concerns as the higher energy EM waves.

This unit is an attempt to inform high school students about some of the fundamental concepts that constitute this important area of science - the food chemistry. Students will review the concepts of chemical compounds, mixtures (solutions, suspensions, colloids and emulsions), physical and chemical changes and learn about food chemistry. They will also learn about some of the most important organic chemistry compounds, the hydrocarbon derivatives or functional groups.

This unit will be tied into students’ chemistry courses, strengthening their knowledge of organic chemistry and preparing them for future college biochemistry, general and organic chemistry classes. The lesson plans require about 12 class periods and cover the concepts of covalent bonds (single, double and triple bonds), functional groups (alcohols, aldehydes and ketones, carboxylic acids, esters, amines, amides) and mixtures (suspensions, colloids, and emulsions). The last lesson is going to cover the basic concepts of hydrophilicity, hydrophobicity, and amphiphilicity of different molecules mixed with water.

This curriculum unit, exploring the energy in food and the thermodynamics of cooking, will include 5 days of 80-minute lessons in which the students will pick a particular food to study. The food will either need to be purchased or produced, and will need to be a food that begins as batter or liquid and solidifies during cooking. For those students who, for any reason, cannot bring in the food, they will be provided a brownie, cupcake, or other common food item. The project will contain two main components or parts. First, the energy stored within the food will be analyzed by applying mathematics. This will require conversion between a common physics unit of kilojoules (kJ) and a common household unit of kilocalories (kcal, CAL or Calories). Students will then need to apply their knowledge of work and energy conservation to provide an example of physical exercise that would be required for them to expend an equal amount of energy that is contained in their food. If a student is uncomfortable sharing their own mass, they may use the common example of a 70-kg person. The second part of their project will involve them using experimental data to determine the heat diffusion constant for their particular food by using a method similar to that described by Rowat et al. published in 2014, “The kitchen as a physics classroom10.” This can be done by placing several thermocouples in their food sample (or probing with toothpicks as will be described later) while heating until the center of the food gets to a desired temperature. Once the diffusion constant is determined, it can then be used to derive an equation that will allow the students to determine the required cooking time based on the size of the food sample. Although larger meals may be interesting samples for the experiment, the food samples must remain reasonably small so that the experiment can be completed within a single class period and can be cooked using toaster ovens or small classroom heaters. Students, in groups of 2-3, will be required to share their data with the class so that the results can be discussed. Students will be graded on their mathematical analysis and an accurate derivation of an equation to predict cooking time based on their measured diffusion constant. Teacher checks will be structured strategically throughout the process to ensure student projects meet the requirements and that student groups remain on pace. By relating energy in food to exercises with equal outputs, and by generating equations to ensure foods will be cooked properly, students not only learn physics in an engaging way but also learn how physics can be used to tackle real-world problems.

The main content covered in this unit includes the Structure and Function of the biological molecules, the energy flow and the nutrients, Nutritional Facts Labels, and the My Plate concept. Proteins, nucleic acids, polysaccharides in carbohydrates are considered macromolecules, and the lipid molecules are considered as biomolecules. For clarity purposes, proteins, nucleic acids, carbohydrates, and fats will be referred to as “biological molecules” throughout the unit. The history of studying these biological molecules dates back to the early 19th century. British physician-chemist, William Prout (1785-1850) was the first to classify “foodstuffs or ingredients of life into saccharinous (carbohydrates), oleaginous (fats), and albuminous (proteins)” and urged that “a satisfactory diet should include carbohydrates, fats, protein, and water”3. Carl Schmidt coined the term “carbohydrates” in 1844.