A mixture of salt water and isopropyl alcohol is immiscible, forming two separate liquids with the organic layer on top and aqueous layer on bottom. When universal indicator is added to such a mixture, all of the indicator compounds in the universal indicator preferentially dissolve in the alcohol--except for phenolphthalein at high pH. Mixtures…

The use of molecular models in chemistry and biochemistry classes is very effective in helping students understand covalent bonds and the chemical structure of molecules. However, conventional molecular models cannot represent intermolecular interactions such as hydrogen bonds and electrostatic interactions. Herein, we describe 3D printed…

Understanding the general ideas and methods of detecting molecular structures is essential in high school chemistry. However, there is a need for more practical activities in teaching. A hands-on activity was designed in this study, which uses flexible foam balls and long sticks such as knitting needles to imitate how scientists construct the 3D…

The initial learning experience is a critical opportunity to support conceptual understanding of abstract STEM concepts. Although hands-on activities and physical three-dimensional models are beneficial, they are seldom utilized and are replaced increasingly by digital simulations and laboratory exercises presented on touchscreen tablet computers.…

The main difficulty in studying molecular symmetry is the mental manipulation of molecules when searching for symmetry. Numerous methods of teaching molecular symmetry require students to identify symmetry elements of objects or molecules. As an alternative, we propose activity that identifies symmetry using elements outside the objects, together…

This report outlines an approach for preparing 5-color 3D printed plastic models of molecular orbitals and electron density surfaces using a hobby-grade 3D printer. Instructions are provided for preparing 3D orbital and electron density surface (EDS) models using solid or mesh representations in ground state and transition state structures. We…

In undergraduate science education, laboratory courses stand as essential cornerstones of experiential learning. Chemistry laboratory courses offer students unique hands-on experiences that bridge the gap between theoretical knowledge and practical application. The journey through the undergraduate chemistry curriculum is paved with a series of…

Single-type, 6-fold symmetrically grooved, and commercially accessible interlocking disks (ILDs) have been used for modeling of sp[superscript 2] hybridized carbon-based nanoarchitectures and complex polyhedral and reticular material models. In the case of the carbon-based nanoarchitectures, we showcase that the primary ILDs can be directly used…

Molecular symmetry is a topic that requires mental manipulation of molecules when searching for symmetry elements and their corresponding symmetry operations. Such mental activities are difficult for students in a traditional classroom where only definitions and demonstrations are provided. Therefore, an exploration-based activity was developed to…

The authors describe the construction and use of tactile models for demonstrating intermolecular forces. These models are composed of inexpensive materials and can be used in college chemistry classrooms of varying levels including general and organic chemistry. The models were designed to be paired with an accompanying activity to encourage…

Gold nanoparticles are exciting materials in nanotechnology and nanoscience research and are being applied across a wide range of fields including imaging, chemical sensing, energy storage, and cancer therapies. In this experiment, students will synthesize two sizes of gold nanospheres (~20 and ~100 nm) and will create gold nanostars utilizing a…

Many STEM (science, technology, engineering, and mathematics) disciplines require a two-semester sequence of introductory college chemistry, which are thus critical gateway courses to a variety of majors. Recognizing the benefit to educators of a structure of content learning across the chemistry curriculum, in 2012, the American Chemical Society…

3D printing was used to prepare space-filling models of electron density isosurfaces and high-resolution molecular models on the basis of the van der Waals radii of atoms. Both model types provide students with kinesthetic simulations of steric effects in bimolecular substitution and elimination reactions. The models can be printed in small sizes…

A safe and inexpensive laboratory for a first-year general chemistry course has been developed which allows students to explore important properties of carbon dioxide, particularly its behavior as a greenhouse gas. Students witness and measure air displacement to compare calculated gas densities and pressures inside a CO[subscript 2]-filled…

Visualization of three-dimensional (3D) elements has always played a huge role in chemistry education. At the same time, it is a challenge to teach with most representations being shown in two-dimensional (2D) media. With the recent rise of extended reality (XR) that includes virtual and augmented reality (VR/AR) technology in higher education,…