PS1a. during chemical reactions the atoms in the reactants
rearrange to form products with different properties.
PS1b. all matter is made of atoms, which may combine to form
molecules.
PS1c. metals have properties in common, such as high
electrical and thermal conductivity. Some metals, such
as aluminum (Al), iron (Fe), nickel (Ni), copper (Cu),
silver (Ag), and gold (Au), are pure elements; others,
such as steel and brass, are composed of a combination
of elemental metals.
PS1d. each element is made of one kind of atom and the
elements are organized in the periodic table by their
chemical properties.
PS1e. scientists have developed instruments that can create
discrete images of atoms and molecules that show that
the atoms and molecules often occur in well-ordered
arrays.
PS1f. differences in chemical and physical properties of
substances are used to separate mixtures and identify
compounds.
PS1g. properties of solid, liquid, and gaseous substances,
such as sugar (C6H12O6), water (H2O), helium (He),
oxygen (O2), nitrogen (N2), and carbon dioxide (CO2).
PS1h. living organisms and most materials are composed of
just a few elements.
PS1i. the common properties of salts, such as sodium chloride
(NaCl).
