# Science as a Human Endeavor

## Calories - Who's Counting?

In this Activity, students determine how many calories are released per gram when marshmallows and cashews burn and then compare the quantity of energy available from carbohydrates versus fats. Students burn the food items beneath a metal soft drink can containing water and measure the resulting change in temperature of the water.

## Millikan: Good to the Last (Oil) Drop

In this Activity, students simulate Millikan’s oil drop experiment using drop-shaped magnets and steel BBs. Students determine the mass of a single BB analogous to the way Millikan determined the charge of a single electron.

## That's the Way the Ball Bounces (or Is It?)

In this Activity, students investigate the physical properties of different balls that may look similar, but have very different rebound properties. Students also investigate how the rebound properties change when the balls are subjected to near freezing and near boiling temperatures. This Activity could be used at the beginning of the school year as an exercise in making observations.

## A Magnetic Meal

In this Activity, students make slurries of breakfast cereal and water and use a magnetic wand to collect elemental iron filings that are present in some cereals. They determine the mass of iron collected and then calculate the "recommended daily allowance" (RDA) in each cereal. An extension uses qualitative tests to confirm that the material collected is actually iron.

## Chemistry of Cement

In this Activity, students use a commercial cement mix to produce concrete. They investigate how changing key variables such as concentrations, curing temperatures, and the addition of various substances affects properties such as setting time, hardness, and plasticity.

## Clip Clues: Discovering Chemical Formulas

In this Activity, students use their deductive reasoning skills as they identify formulas of unknown elements and compounds modeled by paperclips. Each color of paperclip represents a different element, with linkages between different paperclips in appropriate ratios representing 20 unknowns.

## Mass Spectra

In this Activity, students solve puzzles that are analogous to finding the amino acid sequence of a peptide using mass spectrometry. Students identify words that have been broken into letters or groups of letters. In many textbooks instrumental analysis and various types of spectrometry are mentioned only in passing.

## Flame Tests: Which Ion Causes the Color?

In this Activity, students perform simple flame tests using eleven commercially available compounds, cotton swabs, and a Bunsen burner. They then determine whether the cations or anions in each compound are responsible for the flame test colors. This Activity introduces students to flame tests in an inquiry-based manner.

## Whatever Floats (or Sinks) Your Can

In this Activity, students test whether cans of carbonated beverages sink or float in water and then determine whether caffeine content, soda color, or sugar content in the carbonated sodas is responsible for the buoyancy of the sealed cans. This Activity can be used as an introduction to density in a middle school physical science course, or a high school chemistry or physics course.

## How Heavy Is a Balloon? Using the Ideal Gas Law

In this Activity, students explore buoyancy with helium-filled Mylar balloons. They use the ideal gas law to predict the mass of the balloon if it were empty, compare it to the actual mass of the empty balloon, and discuss experimental sources of error. This Activity demonstrates the ideal gas law and introduces students to the concept of buoyancy.