A system and method for guided or unguided instruction, comprising a color, or/and a tactilely coded list of most common ions, and a set, of blocks corresponding to a chart, sufficient to represent formula units in any possible combination of ions coded in the chart, is provided. A valid ionic compound (formula unit) model constructed with the present invention is represented by a rectangular, or cuboid, shape having six sides and eight corners and no more than two ionic types represented by blocks having ionic coding.

Modular frames for instructional use that provide secure mounts for geometric solids are presented. Some contemplated modular frames can be assembled into three dimensional modular devices and are particularly suitable for instructional purposes. Modular devices comprising two or more frames could be coupled via a clip in two or more different configurations. Containers including conductive material and configured to provide a Faraday cage around their contents are also provided.

Modular frames for instructional use that provide secure mounts for geometric solids are presented. Some contemplated modular frames can be assembled into three dimensional modular devices and are particularly suitable for instructional purposes. Modular devices comprising two or more frames could be coupled via a clip in two or more different configurations. Containers including conductive material and configured to provide a Faraday cage around their contents are also provided.

Educational atom models which are attached to a plurality of filaments, to which each end is attached a self-orienting magnet. The magnet is comprised of one magnet or a plurality of magnets, such that the assembly can orient to align, attract and bond to a magnet attached to the end of another filament. The atom models can mimic chemical bonds when a magnet assembly from one atom model orients, attracts and bonds to a magnet from a different atom model. The bonding between magnets more accurately mimics the formation of chemical bonds in terms of force, energy, bonding-electron origin, speed, spontaneity, and atoms' ability to form double and triple bonds. The models are educationally engaging resulting in better learning outcomes.

The present invention is a magnetic hook-and-loop connecting assembly for an ionic disc bonding model, which allow ionic components with positive or negative charges to be strongly attracted to each other, lock together firmly but softly, and yet still be easily taken apart. The core components of the invention are strong magnets (e.g. neodymium or equivalent) and hook-and-loop (Velcro? or equivalent) connectors, which, generally speaking, are configured as follows: a strong magnet embedded into the disc representing the positive, cationic charge has half of the hook-and-loop system attached to it or attached to an intermediate component adjacent to the magnet. The negative, anionic charge has the strong magnet with opposite orientation to the cationic charge and the other connecting half of the hook-and-loop system attached to the magnet or an intermediate component adjacent to the magnet. The invention can be used to strongly attract the components of the ionic disc bonding model representing anions to the components representing cations, hold them in position firmly, yet allow easy separation.

The present invention is a magnetic hook-and-loop connecting assembly for an ionic disc bonding model, which allow ionic components with positive or negative charges to be strongly attracted to each other, lock together firmly but softly, and yet still be easily taken apart. The core components of the invention are strong magnets (e.g. neodymium or equivalent) and hook-and-loop (Velcro? or equivalent) connectors, which, generally speaking, are configured as follows: a strong magnet embedded into the disc representing the positive, cationic charge has half of the hook-and-loop system attached to it or attached to an intermediate component adjacent to the magnet. The negative, anionic charge has the strong magnet with opposite orientation to the cationic charge and the other connecting half of the hook-and-loop system attached to the magnet or an intermediate component adjacent to the magnet. The invention can be used to strongly attract the components of the ionic disc bonding model representing anions to the components representing cations, hold them in position firmly, yet allow easy separation.

A training device for training a user on the operation of an auto-injector that dispenses a medicament. A needle guard is slidable from a first extended position relative to a housing prior to operation of the training device, to a retracted position during operation of the training device, and to a second extended position after operation of the training device. An actuation assembly controls the movement of the needle guard from the retracted position to the second extended position. A lock locks the needle guard in the second extended position. A safety is proximate a proximal end of the housing and prevents movement of the needle guard from the first extended position to the retracted position in a storage position. The needle guard is moveable into the retracted position with the safety in an armed position. The safety resets the lock upon returning the safety to the storage position.

The present disclosure provides a modeling apparatus having a plurality of modeling devices, each having a generally tetrahedron shape having four faces with an interface element attached to each face. Each interface element cane b removably and rotatably coupled to an interface element of an adjacent modeling device. A combination of modeling devices are selectively couplable to form a variety of structures such as molecular, architectural, artistic, dynamic, and/or any other suitable model. The interface elements can include magnets with distinct or identical polarities, and with selective strengths to emulate the target structure or assembly attributes. They can also be iron or a neutral material such as aluminum. The vertices of the modeling apparatus include a curvilinear boundary tracing a spherical periphery of a sphere having a radius extending from a center point of the tetrahedral shape to a midpoint of an edge thereof.

The present disclosure provides a modeling apparatus having a plurality of modeling devices, each having a generally tetrahedron shape having four faces with an interface element attached to each face. Each interface element cane b removably and rotatably coupled to an interface element of an adjacent modeling device. A combination of modeling devices are selectively couplable to form a variety of structures such as molecular, architectural, artistic, dynamic, and/or any other suitable model. The interface elements can include magnets with distinct or identical polarities, and with selective strengths to emulate the target structure or assembly attributes. They can also be iron or a neutral material such as aluminum. The vertices of the modeling apparatus include a curvilinear boundary tracing a spherical periphery of a sphere having a radius extending from a center point of the tetrahedral shape to a midpoint of an edge thereof.

A base unit for use in forming a molecular model has a polyhedral body having a first set of faces defining a plurality of first attachment surfaces, and a second set of faces defining a plurality of second attachment surfaces. A first set of the plurality of second attachment surfaces has a North magnetic polarity, and a second set of the plurality of second attachment surfaces has a South magnetic polarity. The base unit is magnetically coupleable to another base unit in a first configuration in which rotation of the base unit relative to the another unit is inhibited, and in a second configuration in which rotation of the base unit relative to the another unit is not inhibited.