Chemical Reactions and Chemistry Concepts
Initial perceptual naive misconceptions (any age)
- Chemical change changes the atoms themselves.
- Sub atomic particles have the same properties as the elements or molecules
- Molecules have the same properties as the atoms from which they are composed
- Compounds are thought of as mixtures or solutions
- Numbers of particles come and go with out regard to accountability or proportionality of numbers
- Chemical change is like adding something rather than interactive
- Atoms are only in nonliving objects.
- Cells are made of something beside atoms.
- When we die the particles in our atoms stop moving.
- Rust comes from inside the iron object.
Acids and bases
- All acids are dangerous
- All acids dissolve or burn other objects.
- Acids are found in labs or have to be made.
Beginning (preschool - 7 years)
- All things are made from different things.
Intermediate (7 years - 11 years)
- All things are made from chemicals.
- Chemical change changes the substances to different substances.
- Chemical change rearranges the atoms/molecules. Physical change doesn't. Careful saying physical changes are easily reversed. Smashing glass is not easily reversed.
- Sample chemical changes: baking soda and acid = carbon dioxide, baking powder + moisture = carbon dioxide, baking powder + cream of tarter = baking powder (physical change till add moister to the baking powder.
- In most chemical reactions,
energy is transferred into or out of a system. Heat, light, mechanical motion,
or electricity might all be involved in such transfers.
- Matter that has been created naturally on Earth includes 90 different kinds of elements. The smallest piece of any element that is still considered that element is called and atom. or Matter is composed of discrete particles (atoms).
- All of the millions of substances on Earth are composed of different combinations of these 90 basic particles ( atoms) that are created naturally on Earth.
- Over 100 different kinds of atoms
exist; each kind has distinctive
properties, that include mass and
how it will combine with other
atoms or molecules.
- Each atom takes up space, has mass, and is in constant motion. There is nothing but empty space (vacuum) between particles.
- All particles in substances are in
- Particles in motion
have kinetic energy.
- Heat is related to the kinetic energy of the particles with greater kinetic
energy meaning greater heat energy.
- Energy transfers from one particle to another when they collide and is called conduction.
- When particles gain energy they move faster. The faster the particles travel the harder they collide. The harder the collision the farther the particles push each other
apart. This is called expansion.
- Energy transfer causes phase change. Liquids gain energy until they melt and change to a liquid and later evaporate or boil and change to a gas. Gases lose energy until they condense to a liquid or freeze to a solid.
- A solution occurs when one substance breaks down into individual particles (dissolves) and becomes distributed uniformly among the particles of
- During a chemical reaction, starting substances transform into new
substances when the atoms in particles
of the starting substances rearrange to
form new particles.
- Atoms can be joined (in different proportions) to form molecules
that have different
properties than the atoms from which
they are made. The networks between the atoms and/ or molecules are known as chemical bonds
- Organic means related to living or from derived from living matter. Organic compounds always have carbon (most inorganic compounds do not have carbon) and hydrogen or C-H bonds. Having carbon is not sufficient for a compound to be organic. Look for carbon and hydrogen. Examples: Sugar or sucrose (C12H22O11), benzene (C6H6), methane (CH4), ethanol or grain alcohol (C2H6O).