Mr. Matthew Totaro Legacy High School Honors Chemistry The Classification of Matter 1

2 In Your Room Everything you can see, touch, smell or taste in your room is made of matter. Chemists study the differences in matter and how that relates to the structure of matter.

3 What Is Matter? Matter is defined as anything that has mass and occupies space. Even though it appears to be smooth and continuous, matter is actually composed of a lot of tiny little pieces we call atoms and molecules.

4 Atoms and Molecules Atoms are the tiny particles that make up all matter. In most substances, the atoms are joined together in units called molecules. The atoms are joined in specific geometric arrangements.

The Classification of Matter 5

6 Classifying Matter by Composition Matter that is composed of only one kind of substance is called a pure substance. Matter that is composed of different kinds of substances is called a mixture. Pure Sugar Cubes

7 Copper — a Pure Substance

Brass — an example of a Mixture 8 Brass is a mixture of Copper and Zinc

9 Practice—Classify the Following as Pure Substances or Mixtures 24 carat Gold Granite—a rock with several visible minerals in it. Water Iron

10 Practice—Classify the Following as Pure Substances or Mixtures, Continued 24 Carat Gold necklace = pure substance. Granite—a rock with several visible minerals in it = mixture. Water = pure substance. Iron nail = pure substance.

11 Classification of Pure Substances Substances composed of a single type of atom are called elements. Basic building blocks of matter. Composed of single type of atom.  This type of pure substance is found on the periodic table.  Ex: Copper – found on the periodic table with single atoms. Substances that are made of more than one type of atom are called compounds. Chemical combinations of elements. Compounds = two or more different kinds of atoms.  Ex: Table Salt = NaCl, Sodium atoms combined with Chlorine atoms

Copper – an example of an Element 12

Table Salt (NaCl) – an example of a compound 13

14 Classification of Pure Substances 1.Made of one type of atom. (Some elements are found as multi- atom molecules in nature.) 2.Combine together to make compounds. 1.Made of one type of molecule, or array of ions. 2.Molecules contain 2 or more different kinds of atoms. Elements Compounds

15 Practice—Classify the Following as Elements or Compounds Chlorine, Cl 2 Table sugar, C 12 H 22 O 12 Oxygen, O 2 Water, H 2 O

16 Practice—Classify the Following as Elements or Compounds, Continued Chlorine, Cl 2 = element. Table sugar, C 12 H 22 O 12 = compound. Oxygen, O 2 = element. Water, H 2 O = compound.

17 Classification of Mixtures Mixtures are generally classified based on their uniformity. Mixtures that are uniform throughout are called homogeneous. Also known as solutions. Mixing is on the molecular level. Mixtures that have regions with different characteristics are called heterogeneous.

Kool-Aid in Water – a Homogeneous Mixture 18

Chocolate Chip Cookie– a Heterogeneous Mixture 19

20 Classification of Mixtures, Continued 1.Made of multiple substances, but appears to be one substance. 2.All portions of a sample have the same composition and properties. 1.Made of multiple substances, whose presence can be seen. 2.Portions of a sample have different composition and properties. HeterogeneousHomogeneous

21 Practice—Classify the Following as Homogeneous or Heterogeneous A mixture of Kool-Aid and water. A mixture of table sugar and black pepper. A mixture of sugar dissolved in water. Oil and vinegar salad dressing.

22 Practice—Classify the Following as Homogeneous or Heterogeneous, Continued A mixture of Kool-Aid and water = homogeneous A mixture of table sugar and black pepper = heterogeneous A mixture of sugar dissolved in water = homogeneous Oil and vinegar salad dressing = heterogeneous

23 Classifying Matter