What are Chemical Properties & Changes??

Chemical Changes *Chemical change: *matter can undergo a physical & a Chemical change. *Chemical change: occurs when 2 or more substances are combined into entirely new substance with all new properties. *CANNOT CHANGE IT BACK!!!!!

Chemical Changes It’s changing the chemical nature & properties of substances to form new substances.

Chemical Changes Chemical changes alter the composition so that a new substance forms. Examples of Chemical reaction: Match burns, Solution bubbles, 2 substances when mixed they change color.

1-Combustibility It’s a measure of how easily a substance will burn or combine rapidly with Oxygen. Example: toasting Marshmallows. If you burn the marshmallows, you changed it into another substance. ( chemical reaction). ( if you only heat it until it melts???).

1-Combustibility Burning Marshmallows makes Oxygen from the air combines with Carbon in the marshmallow to form Carbon dioxide gas & water vapor. The black, burned area on the marshmallows is Carbon. This change is burning & combustion.

2-Corrosion Its another kind of chemical reaction. When Oxygen in the air combines with Iron Rust forms. (new substance).

3-Reactivity The ability of the substance to go through a chemical reaction. Pouring Hydrogen Peroxide on a wound bubbling occurs. ( Peroxide + blood Oxygen gas ). Another example is fireworks.

Chemical Change Verbs Chemical Change : rusting, rotting, burning, corrosion, reactivity Evidence of chemical change: formation of a gas or solid (precipitate), smoke, fire, an odor, temperature change, color change.

Chemical change examples Baking bread – no longer have flour, eggs, milk, yeast. baking soda & vinegar. Rust.

Conservation of Matter Law Law of Conservation of Mass: composition changes, but mass doesn’t. Chemical changes don’t make new matter, they only make new products from the substances that react. The total mass of the products that form = the total mass of the substances that react.

Conservation of Matter Law The total mass of the products that form = the total mass of the substances that react. Example: iron corroding!! ( matter is conserved)