STUDENT MISCONCEPTIONS

Listed below are some elementary school student physical science misconceptions. The list is not intended to be exhaustive, but rather a summary of some of the more common prior ideas we identified from our analysis of the student response patterns to the items on the tests.

• Matter can be created and destroyed.
• Particles are not conserved in phase changes, e.g., when water evaporates, the evaporated water no longer exists in any form.
• A moving object contains a force given to it by an outside source, and stops moving when the force runs out.
• Air must be involved at some point for sound transmission.
• Energy is an entity contained within substances and can be created and destroyed.
• Heat and cold are substances or entities, and different from one another.
• Electricity flows through hollow wires and is used up by lights or appliances.
• Measurement is only linear.

Listed below are some middle school student physical science misconceptions. The list is not intended to be exhaustive, but rather a summary of some of the more common prior ideas we identified from our analysis of the student response patterns to the items on the tests.

• Gases have no mass.
• Heat and cold are substances or entities, and different from one another..
• Electricity flows through hollow wires and is used up by lights or appliances.
• The eye emits light (or otherwise behaves actively) in order for people or animals to see.
• Appliances or lights can still work in incomplete electrical circuits.
• Matter can be created and destroyed.
• Particles are not conserved in chemical or physical changes.
• Density and other characteristic properties of materials are dependent on the amount of material present. For example, the density of a small piece of rock is not the same as the density of the larger rock from which it came.
• Different forms or phases of the same substances are chemically different.
• Light is unaffected as it passes through transparent materials.

Listed below are some high school student physical science (physics) misconceptions, grouped under the four main standards of the NGSS for grades 9–12 physical sciences. The list is not intended to be exhaustive, but rather a summary of some of the more common prior ideas we identified from our analysis of the student response patterns to the items on all of our field tests, which totaled more than 500 items.

Standard HS-PS2: Motion and Stability: Forces and Interactions

• Students think of force as a property of a single object instead of as a feature of interaction between two objects. Students think that force is something inherent within an object (or that can become part of an object once it is applied, i.e. a push or pull) that keeps it going; moving objects will stop when the force of motion in them eventually runs out.
• Students generally think there cannot be a force without motion, and the force must be acting in the direction of the motion. No motion means no force is acting, and any motion is proportional to the acting force. Forces in opposite directions cancel, no matter what the magnitude.
• Students do not always understand the meaning behind the math, where an equation serves as a "guide to thinking" and not merely a "plug-and-chug recipe for algebraic problem-solving”.
• Students have difficulty with the concept that forces are invisible and think that objects must be in contact for a force to have an effect on the object.
• Objects are either at rest or in motion, where “rest” is regarded as a natural state with no forces acting on an object. An object experiencing a balance of forces is seen as “at rest”.
• Only animate objects can exert a force – thus, if an object is at rest on a table, there are no forces acting on it. Passive objects cannot exert a force.
• Objects fall naturally with no forces involved; barriers stop things falling. Falling objects stay at the same speed as they fall. When dropped in a vacuum, heavier objects will reach the ground first.
• Students often confuse speed, acceleration and velocity, as well as distance–time and speed–time graphs.
• Acceleration can only occur in the same direction as an object is moving. An object cannot have horizontal motion if there are only vertical forces acting on it.
• Students think the speed of an object will increase and then level off at the higher speed when a force acts on an object in the direction of its current motion. Conversely, when a force acts on a moving object to slow it down, the object will slow down for a while and then move at a lower constant speed.
• The motion of an object changes while a new force is being applied (combining with whatever force was acting on it as it was moving), and then goes back to its original motion when that new force ceases. A force “dies out” or “builds up” to account for an object’s speed.
• Students often do not recognize friction as a force, and think friction only occurs between solid objects.
• Students have difficulties in qualitatively interpreting the basic principles related to energy and momentum and in applying them in physical situations. If soft objects collide with each other, momentum does not conserve. For momentum to be conserved, objects must collide elastically. Many students have difficulty understanding the concepts of momentum, conservation of momentum, and confuse momentum and impulse.
• Students have difficulty comprehending what gravity is, how it acts, and where it acts, as well as its interactions and effects on and between objects and fields. Students often do not think there is any gravity in space, and that gravity only relates to Earth.

Standard HS-PS 3: Energy

• Energy is thought of as a force, or a causal agent that is stored in certain objects. Energy is an “ingredient” of objects and lies dormant within the object until something triggers it. Energy is assumed to arise all of a sudden as a result of some combination of “ingredients” rather than being thought of as continuous.
• Students’ descriptions of energy are often very anthropomorphic and anthropocentric; energy is mainly associated with human beings; nonliving things are thought not to need energy.
• There is the idea of a “depository” model of energy: some objects are thought of as having energy and being rechargeable, some objects needing energy and using what they get, some objects are neutral. Students think of energy as fuel or a fuel (often instead of fuel “containing” energy or “as a source of” energy).
• Energy is movement of any kind (i.e. the energy is the movement), and movement requires energy. Energy is the overt, outward display of activity (and is the sole means of identifying energy). An object has energy within it that is used up as the object moves.
• Students think of a battery as a “giver” of electricity (as a store of electricity or energy) and is a constant current source, creating energy out of nothing. They are uncertain of the role of a battery. When an electrochemical cell no longer works, it is out of charge and must be recharged before it can be used again.
• Most students do not have a clear understanding of the underlying mechanisms of electric circuit phenomena. Some may think electricity is used up by a circuit. Students often think of current as energy and assume electrical energy flows inside metal wires.
• Students lack knowledge about the individual forms of energy. One form of energy cannot be transformed into another form of energy (e.g. chemical energy cannot be converted to kinetic energy). Convection is the most difficult energy transfer concept for students.
• Students broadly have difficulty with the concepts of conservation of energy. Energy is not conserved, it is seen as a short-lived product that is generated, is active, and then fades and disappears. Things go until energy is used up or fuel is consumed; things use up energy. Students think that energy can be created or destroyed.
• Energy is thought to flow out of one thing and into another. Energy is not transferred from one object to another unless those objects are in direct contact with each other.
• In terms of conduction, students often think that when a cold and a warm object are placed in contact with each other, the warm object gets colder and the cold object gets warmer because “coldness” is transferred from one object to the other (particularly involving frozen objects).
• Thermal energy will continue to be transferred by conduction even after objects in contact with each other reach the same temperature; the temperature of the object getting warmer will continue to increase and the temperature of the object getting cooler will continue to decrease.
• Only objects that are warm or hot have thermal energy and can transfer thermal energy. Heat and temperature are the same thing.
• Earth gets heat from the Sun (rather than light from the Sun reaches Earth and is absorbed, increasing the energy in an object causing the object to heat up).
• Students have difficulty understanding the concept of gravitational potential energy.
• Students have a variety of incorrect ideas regarding “motion energy”, lacking an understanding of the relationship of “motion energy” to an objects’ size, mass, speed, material make-up, shape, or direction of travel. Students claim that PE and KE cancel out.
• Many students have difficulty distinguishing between a system and its surroundings and do not consider the interactions between a system and its surroundings. Students assume that the energy of any system is always constant (since “energy is always conserved”), regardless if there is external work done on the system (i.e. block and spring).
• Students tend to associate energy with objects (batteries and fuels) rather than abstract processes and constructs (heat and light).
• “Energy” and “force” are commonly confused by students and thus used interchangeably. Students have difficulty thinking about forces across fields.

Standard HS-PS4: Waves and Their Applications in Technologies for Information Transfer

• In general, people use or experience technology, but do not understand electromagnetic radiation nor how a cell-phone works. Many people believe that all imaging involves radiation, which is dangerous to everyone.
• Many students think electricity that flows in wires is supplied by a generator such as a battery or photovoltaic cell instead of being “pumped” or “moved” by those mechanisms.
• Students often think light is a form of energy (instead of a carrier of energy).
• Many students have incorrect mental models of waves and use these erroneous models to interpret problems related to wave mechanics, such as when waves meet, they interfere, and then bounce back to where they originated.
• Students think that waves involve the transport of matter from the source to a distant location, and that waves carry the particles of the medium with it rather than being temporarily displaced and returning to their original position.
• Students confuse wave frequency and wave speed and have difficulty with the vocabulary in describing waves and wave patterns.
• Students do not always discern a standing wave from a standing wave pattern resulting from the interference of two waves.
• Light waves and radio waves are not the same thing, much like gamma rays, x-rays, ultraviolet light, visible light, infrared light, microwaves and radio waves are all very different entities versus all being part of the electromagnetic spectrum.
• Few students of any age describe the transfer of vibrations of an object to the surrounding air. When an object is not seen as obviously vibrating (two stones whacked together), most students refer to personal actions and properties of the object (i.e. stones) in reference to the source/production of the sound.
• Students think sound needs an unobstructed pathway to travel and seems to be related to everyday experiences of movement and impediments to movement (having to go around an object to get through).
• Waves can't have particle properties, and do not have energy.
• Waves transport matter and there must be a medium for a wave to travel through. All waves travel the same way, and big waves travel faster than small waves in the same medium.
• Students think that the spectrum of electromagnetic radiation consists of only visible light, and different colors of light are different types of waves.
• Students do not always distinguish between mechanical waves and electromagnetic waves; mechanical waves, such as a sound wave, cannot travel through a vacuum while electromagnetic waves have an electric and magnetic nature and are capable of traveling through a vacuum.
• Energy cannot be transferred from one object to another object. Only objects that are glowing can transfer energy in the form of electromagnetic radiation.
• An object cannot absorb and reflect light – it must do one or the other. Earth gets heat from the sun (instead of Earth gets light from the sun), either reflected or absorbed by an object on Earth.
• Heat and light from the sun are necessary for solar cells to work and generate current. Light is what gives the energy: “photons come in, deliver energy to the electrons and the electrons get ejected”.

Listed below are some student physical science misconceptions, grouped under the four main standards of the NGSS for grades 9–12 physical sciences (chemistry). The list is not intended to be exhaustive, but rather a summary of some of the more common prior ideas we identified from our analysis of the student response patterns to the items on all of our field tests, which totaled more than 500 items.

Standard HS-PS1: Matter and its Interactions

• Students exhibit confusion between everyday usage of scientific terms and application of these terms.
• Atoms can be seen with a microscope; atoms are microscopic versions of elements—hard or soft, liquid or gas.
• Electrons in an atom orbit its nucleus like planets in our solar system orbit the sun.
• Students have difficulty accepting the notion of “empty” space; there must be air, dust, or other gases – “something” -- between particles. No space is completely empty, both within atoms (as between nuclei and electron clouds) or between particles in solids, liquids.
• Secondary students can depict the solid state as an ordered arrangement of molecules but do not give reasons for why it holds together or is incompressible.
• The particles of a solid never move.
• Particles are mini-versions of the substances they comprise and possess the same properties.
• The expansion or contraction of matter is due to corresponding changes in the constituent particles, and not the space between the particles.
• There are no bonds in elementary substances, e.g., in a piece of pure gold.
• There is much confusion among students about regarding the arrangement of and trends within the Periodic Table, along with confusion of terms and categories used to discuss the Periodic Table. Students confuse periods (rows) and groups (columns), unaware that columns are vertical and periods are horizontal, likely due to a lack of understanding of nomenclature.
• An element is a particular kind of chemical, and all molecules are atoms/molecules of the same substance.
• Behavior of electrons and different types of and energies involved in bonding prove difficult for students to grasp and adequately explain.
• There is confusion between bond being material links rather than forces.
• Students often memorize chemical equations without sufficient understanding.
• Students often describe the result of a chemical reaction as something, i.e., a new substance simply “appears” or “is produced” while something else “disappears” or “is used up” without understanding the events in a chemical reaction, including that the rearrangement of atoms to produce a new substance is involved.
• There is often the notion of existing matter being destroyed and new matter created in a chemical reaction, and that energy is “used up”, “caused by”, or “made by” something in these reactions.
• Students do not always comprehend that the total number of atoms, not the number of each kind of atom, is always conserved, and the total number of molecules is always conserved.
• When studying a reaction at equilibrium in which there is no longer an observable change, students do not appreciate that a dynamic process is at work.
• Students have a wide range of topic-specific difficulties associated with understanding types of chemical reactions that occur under different conditions, i.e. combustion reactions, acid-base reactions, and redox processes.
• Students have difficulty in making the distinction between noble gas stability and nuclear stability or the stability of the nucleus of an atom and the chemical stability of an element.

Standard HS-PS3: Energy

• Students do not always understand that one form of energy cannot be transformed into another form of energy; it is often described as a “product” or by-product of a process or situation.