Reactions
8-5. Chemical
reactions are processes in which atoms are rearranged into different
combinations of molecules. As a basis for understanding this concept:
8-5-a. Students
know reactant atoms and molecules interact to form products with
different chemical properties.
5-1-a Students know that during chemical reactions the atoms in
the reactants rearrange to form products with different properties.
5-1-a Students know that during chemical reactions the atoms
in the reactants rearrange to form products with different properties.
5-1-f Students know differences
in chemical and physical properties of substances are used to separate
mixtures and identify compounds.
- Chemical reactions
- electrolysis
- rapid oxidation
- vinegar and baking soda
- dissociation of salt in water (conductivity)
- Physical reactions
- distillation
- boiling point elevation (probeware)
- dissolving (sugar in water)
- iron in sand (separation with magnet)
8-5-b. Students
know the idea
of atoms explains the conservation of matter: In chemical reactions
the number of atoms stays the same no matter how they are arranged,
so their total mass stays the same.
8-5-c. Students
know chemical
reactions usually liberate heat or absorb heat.
- Exothermic and endothermic reactions; handwarmers,
ice packs, sulfuric acid & sugar
- Endothermic reactions
8-5-d. Students
know physical
processes include freezing and boiling, in which a material changes
form with no chemical reaction.
- Distillation apparatus (2.4.4)
- Hero's engine
- Air pressure, collapsing can, air pressure fountain
8-5-e. Students
know how to determine
whether a solution is acidic, basic, or neutral.
- Anthoncyanin pH indicator: household chemistry
(5.5.3)
- Respiration activity
(5.6.5)
