Physical and Chemical Properties

All substances have properties… Including people! Example: People can be identified by their … Face (shape, expressions) Voice Height Finger prints Eye color Hair color Teeth DNA

Physical Properties Physical properties are used to identify, describe and classify matter. Characteristic of a substance that can be observed (using your senses) without changing the substance into something else. Phase Texture Color Odor Taste Temperature

Creating a new chemical product Chemical Properties Chemical properties are characteristics involved when a substance interacts with another substance to change its chemical make-up. Flammability Rusting Creating gas bubbles Creating a new chemical product Reactivity with water pH

Show Me the Answer! Use your hand to make a “P” if you think the picture is showing a physical property and a “C” if you think its showing a chemical property.

Phase change Physical

Boiling Point Physical Rubbing Alcohol boils at 90 degrees Celsius Water boils at 100 degrees Celsius

Flammability (ability to burn) Chemical

Rusting Chemical

Odor Physical

Carbon Dioxide CO2 Chemical

Physical Changes vs. Chemical Changes.. Now lets talk about Physical Changes vs. Chemical Changes.. BACK TO THE NOTE SHEET!!!!!

Physical Changes Physical Change: a change in matter that does not change the identity of a substance or produce a new substance—it keeps the same chemical composition.

Examples of Physical Changes: Phase changes (solid to liquid to gas) After: H20 (gas) Before: H20 (liquid)

Examples of Physical Changes: Breaking, tearing, ripping, cutting, crushing Homework before The object’s appearance has changed but the object is still made of the same particles Still homework after…

(still the same chemical makeup.) Examples of Physical Changes: Dissolving (A sugar cube is still sugar after it dissolves in water.) Sucrose (C12H22O11) Sugar Water (still the same chemical makeup.) Water (H2O)

Examples of Physical Changes: Changing size, shape, or amount Cookie dough AFTER….(just a different shape) Cookie dough BEFORE….

A snowman melting is an example of a physical change A snowman melting is an example of a physical change. The puddle of water and the snowman are made of the same matter—H20! H2O molecules as a gas. Particles move fast and are farther apart. H2O molecules as a solid. Particles are close and vibrate in place. H2O molecules as a liquid. Particles slide past one another.

Chemical Changes Chemical Change: a change in which a new substance is formed, or when one substance is changed into another (i.e., it changes the chemical composition).

Clues of a Chemical Change: A new substance is produced Iron (Fe) Rust(Fe2O3) Oxygen (O2)

Clues of a Chemical Change: Bubbles are produced (indicates presence of a gas)

Clues of a Chemical Change: Change in color or new odor (smell) produced. Aluminum and Iodine

Clues of a Chemical Change: Energy (heat/light) is given off (substance feels) or taken away (substance feels cool) during the chemical reaction. Ammonium Experiment

Wood will never go back to original form Clues of a Chemical Change Irreversible (can’t change it back)* When you cook something, it can never go back to the original composition. Wood will never go back to original form

During a chemical change, matter with a new chemical composition and new properties is formed. Examples of chemical changes include: the burning of wood, cooking of food, rusting of iron, tarnishing of silver, digestion of food, and souring of milk. All of these are examples of chemical changes because the matter created has new chemical compositions and different properties than the matter from which it was formed.