The concepts developed in this standard
· All matter – regardless of its size, shape, or color – is
made of particles (atoms and molecules) that are too
small to be seen with the unaided eye.
· There are over 100 known elements that make up all
matter. The smallest part of an element is an atom.
· When two or more elements combine to form a new
substance, it is called a compound. There are many
different types of compounds, because atoms of
elements combine in many different ways (and in
different whole number ratios) to form different
compounds. Examples include water (H2O) and table
salt (NaCl). The smallest part of a compound is a
· A mixture is a combination of two or more substances
that do not lose their identifying characteristics when
combined. A solution is a mixture in which one
substance dissolves in another.
· As its temperature increases, many kinds of matter
change from a solid to a liquid to a gas. As its
temperature decreases, that matter changes from a gas to
a liquid to a solid.
In order to meet this standard, it is expected that students
should be able to:
· construct and interpret models of atoms, molecules,
elements, and compounds.
· design an investigation to determine how heat affects the
states of matter (of water). Include in the design how
information will be recorded, what measures will be
made, what instruments will be used, and how the data
will be graphed.
· construct and interpret a sequence of models (diagrams)
showing the activity of molecules in all three states of
· compare and contrast: mixtures and solutions; elements
and compounds; and atoms and molecules.