Red onion, "Allium cepa," juice can dye a cloth sample green upon the addition of alum, aluminum potassium sulfate, and this sample can turn red when subjected to an acidic solution. When the red-colored sample is washed with a neutral or alkaline aqueous solution, its color turns green again. These experiments illustrate color changes…

For nearly two decades, augmented reality (AR) has found diverse applications in education, particularly in science education, where its efficacy has been supported by relevant theories and many empirical studies. However, previous studies have revealed the following research deficit: While AR technology appears to influence learning-related…

By hosting a college students' laboratory skills contest, we provide an interesting activity for students to cultivate good laboratory practices and thereby improve their laboratory skills. The substance of this contest is the detection of the hardness of water, which involves numerous laboratory skills such as solution preparation, weight by…

With the increase of waste paper, environmental pollution and atmospheric impact have become global problems. The cellulose contained in waste paper has the advantages of being renewable and biodegradable and can be applied to many fields to achieve sustainable development. At present, thermal management materials, as a new type of material, have…

In the light of own measurements on a Faraday generator, the well-known theories concerning Unipolar Induction and the Faraday paradox seem to be problematic. On the other hand, all results obtained, and all other processes described as a paradox in connection with the Faraday generator can be explained without contradiction based on the theory of…

Two balls on an incline can remain at rest if friction between the balls prevents them rolling down the incline. Results with various balls are presented to show how ball mass, diameter and friction affects the outcome. A stack of four identical balls is also examined.

We adapted a classical asymmetric Michael addition for a 1 day experimental session (6-8 h) for third- or fourth-year undergraduate students. The experiment contains three steps: synthesis of a chiral Lewis acid, LiAl((S)-BINOL)[subscript 2], then its use as a catalyst in the Michael addition of diethyl malonate on cyclopentenone, followed by…

A standard physics experiment for students is to measure the terminal velocity of an object in air or in glycerine. A more difficult challenge is to measure the terminal velocity in water since the depth of the water needs to be large or the object needs to be dropped in the water at a speed close to its terminal velocity. Results obtained by…

One step of the published mechanism of the hydrogen peroxide iodine-clock reaction is called into question by the result of an experimental attempt (predicated on that mechanism) to integrate that reaction into the elephant's toothpaste demonstration to reveal and control its iodine side product. Under conditions that were a hybrid of those…

Carbonated beverages have long provided chemical educators and other teachers of science with an easy-to-obtain system that connects to several physicochemical concepts. For example, many educators have devised experiments to determine the pressure of CO[subscript 2] contained in commercial carbonated beverages, but the role of temperature in such…

In this paper we consider the well-known experiment with the 'heavy' newspaper that breaks a stick that it is laid on. Using several appropriate control experiments we show that the currently invoked explanation using atmospheric pressure cannot be correct. We perform a theoretical analysis and propose a new explanation based on the rotational…

This paper introduces a safe, interesting, convenient, and low-cost experiment. The products of galvanic cells and electrolytic cells are compressed into specimens that are placed on a slide to stretch the metal dendrites in one plane and ensure they are not easily destroyed by external factors. The details and growth process of the metal…

A previous journal article established that a hanging Slinky's restoring force is due only to the coils between the support and the Slinky's center of mass (hereafter COM). Correspondingly, it is expected the Slinky's elastic potential energy (hereafter EPE) is associated with only those coils; however, there is no confirming experimental…

According to Einstein's general theory of relativity, a clock runs more slowly if it is close to a large gravitating object. This principle was highlighted in the movie "Interstellar," in which the main character spends several hours on a planet orbiting a massive black hole, and returns to find that his young daughter has become an…

Understanding experimental design (e.g. control of variable strategy or CVS) is foundational for scientific reasoning. Previous research has demonstrated that demonstrations with cognitive conflict (e.g. asking students to evaluate and explain different experimental designs) are effective in promoting children's scientific reasoning, however, the…