Do NowToday we will be discussing the differences

between Heterogeneous and Homogeneous mixtures. Copy the following:

The words Heterogeneous and Homogeneous have Latin pre-fixes, which mean –

Hetero – DifferentHomo – Same

Physical Science February 17th 2011

SWBAT define the difference between a heterogeneous mixture and a homogeneous mixture

Homework Review• State the relationship between atoms and

elements. Are both atoms and elements matter?– An atom is the smallest unit of an element that has

that element’s properties. Both atoms and elements are matter.

• List two types of pure substances:– Elements– Compounds

• Describe matter, and explain why light is not matter. Is light made of atoms and elements?– Matter has mass and takes up space. Light has no

mass or volume and no atoms. • Define molecule, and give examples of a

molecule formed by one element and a molecule formed by two elements– A molecule is the smallest unit of a substance

that keeps all physical and chemical properties of a substance. Oxygen (O2) is an example of a molecule formed by one element. Water (H20) is a molecule formed by two elements.

• Classify each of the following as an element or compound:– A. Sulfur (S8)• Element

– B. Methane (CH4)• Compound

– C. Carbon monoxide (CO)• Element

– D. Cobalt (Co) • Compound

• State the chemical formula for water.– Water has 2 hydrogen and 1 oxygen atom = H2O

• Compare and contrast mixtures and pure substances, give an example of each.– A pure substance has the same composition

throughout. – A mixture has more than one pure substance.

Mixtures• Most matter in the

universe is found in mixtures.

• A mixture is made from two or more substances either elements, compounds or both - that are not chemically combined.

Mixtures and compounds differ in

two ways…

Substances in a mixture keep their individual properties.

Parts of a mixture are not necessarily present in specific ratios.

Compound• A compound has properties different than the

elements that make it up.• The parts of a compound are present in

specific ratio’s.

+ =

Hydrogen (g)

Water – H20 (l)

Other Compounds

Compounds and Mixtures• Most of the matter around you is in the form

of compounds or mixtures.• Water, carbon dioxide, salt, vinegar, baking

soda, lye, sugar, gasoline, and bleach are all chemical compounds.

Heterogeneous Mixture• A mixture in which different materials can be

easily distinguished.• Examples: Pizza, trail mix, beach sand, bird

seed, oil & water, dirt

Solutions

• Homogeneous mixture: is a substance in which two or more substances are uniformly spread out.

• Solution is another term for homogeneous mixture.• Examples: Salt water, gasoline, vinegar, hand lotion

Miscible VS. Immiscible• Miscible – when two liquids are mixed together and

they are evenly spread.– Gasoline

• Immiscible – when two liquids do not mix together– Oil & water

Today’s Assignments

• Classwork– Mixture Worksheet– We will spend approximately 5-7 minutes per

section then review it and move on!• Homework– “Science and the Consumer”– Page 43– Read and answer both questions in notebook

Classwork Review1. Identify each of the following samples of

matter as: homogeneous matter or heterogeneous matter

• (a) spaghetti sauce - heterogeneous • (b) table sugar - homogeneous • (c) cough syrup - homogeneous • (d) glass - homogeneous • (e) river water - heterogeneous • (f) nitrogen - homogeneous

• 2. Classify each of the following as: element (ele) or compound (com) or mixture (mix)

• (a) spaghetti sauce - Mixture• (b) table sugar - Compound• (c) cough syrup - Mixture• (d) silver - Element (Ag)• (e) orange juice - Mixture (Water & Oranges)• (f) iced tea - Mixture • (g) glass - Mixture• (h) river water - Mixture• (i) nitrogen- Element (N)• (j) Phosporous - Element (P)• (k) oxygen - Element (O)• (l) air - Mixture

• 3. Choose words from the following list to fill in the blanks in the sentences.

• mixture heterogeneous matter substance• compound homogeneous matter element• (a) Matter that has uniform characteristics throughout is called

HOMOGENEOUS MATTER• (b) Matter that has parts with different characteristics is

called HETEROGENEOUS MATTER• (c) A simple substance that cannot be broken down into other

substances by chemical means is called a(n) ELEMENT• (d) A chemical combination of simple substances is called a

COMPOUND• (e) A physical combination of different substances that retain

their individual properties is called a(n) MIXTURE• (f) Either an element or a compound may be referred to as a

SUBSTANCE

Part 4

• "The components of a mixture can be separated by physical means; a compound must be chemically broken apart into its components. A mixture has a variable composition; a compound has a definite composition."

• 5. Classify these samples of matter as a: substance / homogeneous mixture / heterogeneous mixture

• (a) copper - Substance• (b) ink - homogeneous mixture• (c) glue - homogeneous mixture• (d) carbon mixed with sand - heterogeneous

mixture• (e) water containing dissolved salt –

homogeneous mixture• (f) flower – heterogeneous mixture• (g) oxygen dissolved in water – homogeneous

mixture• (h) apple juice – homogeneous mixture

• 6. Classify each of the following as a: element / compound / homogeneous mixture / heterogeneous

mixture • (a) water - compound• (b) air - homogeneous mixture • (c) sugar dissolved in water - homogeneous mixture • (d) granite - - heterogeneous mixture • (e) sand in water - heterogeneous mixture • (f) peanut butter - heterogeneous mixture • (g) carbon - element• (h) table salt - compound• (i) homogenized milk - homogeneous mixture • (j) oxygen - element• (k) blood - heterogeneous mixture • (l) motor oil - homogeneous mixture

• 7. Fill in the blanks with:• element / compound / homogeneous mixture / heterogeneous

mixture • (a) Steel contains mostly iron plus trace amounts of at least one other

element. You could have heard of various kinds of steel, stainless steel, cobalt steel, tungsten steel. Since the composition of steel can vary, it is a homogeneous mixture.

• (b) Hydrogen is listed on the periodic table. It is a Element.• (c) Milk is a homogeneous mixture because it consists of more than one

component, and its composition varies. For example, you have probably seen whole milk, 2% milk, and non-fat milk at the grocery store. These three grades of milk all differ in their fat content.

• (d) Table salt is composed of the elements sodium (Na) and Chlorine (Cl) in fixed proportions. It is a compound.

• (e) Seawater contains sodium chloride and many dissolved minerals. The composition of seawater changes from place to place. Some seawater is high in dissolved minerals, but in other regions the seawater is lower in minerals. Since its composition is variable, seawater must be a homogeneous mixture.