Changes in MatterPhysical Change - when a substance is

changed, yet retains its compositionex. sheet of aluminum foil rolled up into a

ball, smashing a crystal, or cutting paper

Phase Change - transition from one state to another, still a physical change, based on temperature and pressure of the surroundings

Changes in MatterPhysical Change - Water Cycle is a great example

of physical changes.

as water goes through different pressures and temperatures, it is seen in its 3 phases (solid, liquid, and gas)

Changes in MatterPhysical

ChangesMelting Point - temperature and pressure at which a solid phase changes to a liquid

Boiling Point - temperature and pressure at which a liquid phase changes to a gas

ex. what are the boiling and melting points of water?

Melting and Boiling points are intensive properties that can be used to identify unknown substances through experimentation.

Changes in MatterChemical Change - process that involves one or

more substances changing into different substances

commonly referred to as a chemical reactionthe "new" substance formed from a chemical

reaction has different properties than the substances did before the reaction

the substances involed before the reaction are called REACTANTSthe substances created through the reaction are called the PRODUCTS

Changes in Matterex. when iron is left exposed to air containing

oxygen, a reaction occurs creating rust (iron oxide) which has different properties than either the iron or the oxygen

the rust is not attracted to magnets, while the iron is

ex. when food spoils, the look, feel, smell, and taste of the new product differ from the original food, as well as the digestability of the spoilt food

Changes in MatterConservation of

Masslate 1700s - development of more precise scales

measurements during reactions showed that total mass before and after reactions was constant, no change in

mass

LAW OF CONSERVATION OF MASS developed from the findings, stating that mass is neither created or destroyed during a chemical reaction, it is conserved.

in other words, the total mass of reactants will equal the total mass of the products

Changes in Matterexample - In an experiment, 10.00g of red

mercury oxide powder is heated in an open flask until it is converted to liquid mercury and oxygen gas. The liquid mercury has a mass of 9.26g. What is the mass of the oxygen gas formed in the reaction?

Massreactants = Massproducts

10.00g (mercury oxide) =

9.26g (mercury liquid) + ____ g (oxygen gas)

10.00g - 9.26g = 0.74g