Unit 1Lesson 4 Pure Substances and Mixtures
A Great Combination
How can matter be classified?
•Matter is made up of basic “ingredients” known as ____________________
•An atom is the smallest unit of an element that maintains the __________________of that
element.
•_____________________________are classified as elements, compounds, and mixtures.
How can matter be classified?
•An _______________________ is made of only one kind of atom.
•Example: Gold is made of only gold atoms, oxygen is made of only oxygen atoms.
•A ________________ is a molecule that is made up of different kinds of atoms that are
chemically combined.
•Example: Water (H2O) is a molecule made of Hydrogen and Oxygen atoms that are combined
______________________.
•A mixture contains a variety of elements and that are ______________ chemically combined.
•Example: Salt water is a mixture of salt (NaCl) and water (H2O) but are NOT
_____________combined.
How can matter be classified?
•Is water an element, a compound, or a mixture?
What are pure substances?
•A pure substance is a substance with definite ____________ and
________________properties.
•Pure substances are made up of just _______________type of element or molecule.
•Elements and compounds are _________________substances.
What are pure substances?
•______________________ changes such as melting, freezing, cutting, or smashing do not
change the identity of pure substances.
•Example: Water can be boiled into a gas and frozen into a solid, but will always be ________.
•Example: Iron can be cut, bent and melted, but will always be ____________________
•When a pure substance undergoes a chemical change, it is no longer that
_____________substance.
•Example: Water can be separated into its original elements (Hydrogen, Oxygen) using a
chemical process called ________________________
How can elements be classified?
•_____________________________are classified as metals, nonmetals, or metalloids.
•Classifying elements helps scientists predict the _______________________of elements.
•The _____________________________table is a tool used to classify and identify elements
that have similar properties.
How can compounds be classified?
•__________________________ can be classified as acidic, basic, or neutral by measuring pH
•Pure water has a pH of 7. Acids have a pH below 7. Bases have a pH above 7.
•Blue litmus paper turns red in the presence of an _______________________
•Red litmus paper turns blue in the presence of a ________________________.
How can compounds be classified?
•___________________________can be organic or inorganic.
•_______________compounds are those that contain a combination of carbon and hydrogen
•Organic compounds made by ________________________ things are called biochemicals.
•Carbohydrates, lipids, proteins, and nucleic acids are biochemical compounds.
What are mixtures?
•A mixture is a combination of two or more substances that are combined
_______________but not _________________________.
•______________________ are not pure substances and do not have definite properties.
•The _____________________________of a mixture can change depending on the amount of
each material being mixed.
What are mixtures?
•Substances within a mixture keep their identities and individual ________________________
•Mixtures can be __________________by physical changes, although some mixtures are
difficult to separate.
•Magnets, centrifuges, filters, and other materials can be used to separate mixtures.
How can mixtures be classified?
•A ___________________________ mixture is one that does not have a uniform composition.
•A _________________________________s mixture has the same composition throughout.
Heterogeneous Mixtures
•A __________________________is a heterogeneous mixture.
•________________________in a suspension are spread throughout a liquid or gas, but are
too large to stay mixed unless shaken or stirred.
•Particles __________________________________in suspensions.
Homogenous Mixtures
•A solution is a ______________________mixture in which one substance is dissolved in
another substance.
•____________________shave particles that are unevenly spread throughout the mixture.
•Unlike a suspension, particles in _________________are too small to settle out of the
mixture.