Water electrolysis, a well-known and simple experiment, confirms that a water molecule comprises hydrogen and oxygen atoms. In this experiment, hydroxide or hydrogen ions generated from each electrode were identified using an indicator based on the assumption that electrodes, electrolytes, and indicators do not participate in the water…

In this guided-inquiry lesson, students were tasked with determining the efficacy of an at-home drinking water filter at removing lead (Pb) from tap water using graphite furnace atomic absorption spectroscopy by determining the concentration of lead before and after filtration. The lesson was structured to allow students to choose and perform…

The California Blackworm ("Lumbriculus variegatus") is a freshwater segmented worm species that has been used by biology instructors as a model system for inquiry-based student investigations. The blackworm dorsal blood vessel pulsation rate is easily quantified. Moreover, this species can facilitate the study of neuromuscular…

This paper proposes an experiment in which students build microdevices for conveniently electrolyzing water and use image recognition and processing technology to measure the volume of gas generated during the reaction in a noncontact way. Taking advantage of three ratio relationships between (i) gas volume and the area of bubbles, (ii) the…

In 2018 the Gulf coast of Florida suffered extensive damage from harmful algal blooms (HABs), from as far north as Clearwater Beach south to Naples. The bloom lasted nearly a year, picking up in intensity during the late summer months. HABs occur when conditions such as reduced salinity, higher water temperatures, light saturation, and currents…

This study focuses on the design of a learning program to introduce complexometric titration as a method for determining water hardness in a high school chemistry laboratory. Students are introduced to the different properties and reactions of hard water in a stepwise manner so that they gain the necessary chemical knowledge and conceptual…

We describe an activity-based approach for teaching aqueous solubility to introductory chemistry students that provides a more balanced presentation of the roles of energy and entropy in dissolution than is found in most general chemistry textbooks. In the first few activities, students observe that polar substances dissolve in water, whereas…

The inquiry-based approach to learning has proven to be quite effective, since Socrates, but it is difficult to found good questions to induce reasoning. Many sources explain wrongly some experimental results, which can be used as discrepant events. Some use the breaking of a ruler with a newspaper to "show" that the atmospheric pressure…

Science teachers can find lesson ideas almost anywhere. For example, during a recent visit to a local dollar store, the author stumbled upon a flower vase filled with water pearls, also known as water beads and jelly beans. She bought several of the bags (search the web to find numerous online sources), and soon began experimenting. Water pearls…

A recipe is a great way to learn about the procedure and the variables (or "ingredients") involved. Cookbooks are comforting and valuable: They're easy to follow, and people know what they'll get. The problem is that cookbook labs end just when things get interesting. The excitement of science is in understanding the discovery and pursuing the…

We present a hands-on, inquiry-based activity exploring how CO[subscript 2] input to seawater affects the skeletons of several species of reef-building corals and other marine organisms by testing for changes in pH and calcium ion concentrations. Originally developed to inspire and recruit high school students in the state of Hawai'i into the…

As a result of shifting marine environmental conditions caused by global climate change and localized water pollution, marine organisms are becoming increasingly exposed to changing water quality conditions. For example, they are exposed to more extreme salinity fluctuations as a result of heavier rainfall, melting polar caps, or extreme droughts.…

Hydroponics is a process in which plants are grown using nutrient-rich water instead of soil. Because this process maximizes the use of water and nutrients--providing only what the plant uses in controlled and easily maintained systems--it is a viable alternative to traditional farming methods. The amount of control in these systems also ensures…

This article describes an activity that can be used as an inquiry-based laboratory or demonstration for either high school or undergraduate chemistry students to provide a basis for understanding both vapor pressure and the concept of dynamic phase equilibrium. The activity includes a simple setup to create a closed system of only water liquid and…

The International Boiling Point Project is an online, collaborative project for students in grades 6-12 in which they investigate the impact of four factors (room temperature, elevation, volume of water and heating device) on the boiling point of water. A detailed procedure is provided for students in order to limit the number of variables…