Matter – Properties and Changes Chapter 3

3.1 – Properties of Matter  Matter is anything that has mass and takes up space (mass is the amount of matter the object contains).  What’s the difference between mass and weight?  Substances are matter that have uniform and unchanging composition.  What is an example of a substance?

States of Matter  What are the three states of matter?  Solid – Form of matter that has its own definite shape and volume.  definite shape and volume, incompressible  Liquid – Form of matter that flows, has constant volume, and takes the shape of its container.  indefinite shape, definite volume, incompressible  Gas – Form of matter that not only flows to conform to the shape of its container but also fills the entire volume of its container.  indefinite shape and volume, compressible  What is the difference between a gas and vapor?  Vapor refers to the gaseous state of a substance that is a solid or a liquid at room temperature.

Physical Properties of Matter  A physical property is a characteristic that can be observed or measured without changing the substance’s composition.  Extensive – dependent on the amount of substance present. (such as mass)  Intensive – independent of the amount of substance present. (such as density)  Name more examples of physical properties.

Chemical Properties of Matter  A chemical property has the ability or inability to combine with or change a substance into one or more other substances.  What is an example of a chemical property?

3.2 – Changes in Matter  What are the two types of changes matter can undergo?  Physical Change – alters a substance without changing its composition.  Phase Change – Transition of matter from one state to another.  Water Cycle – boil, freeze, condense, vaporize, melt  Chemical Change – process that involves one or more substances changing into new substances.  What are some examples of evidence of a chemical change?

Conservation of Mass  The law of conservation of mass states that in any physical change or chemical reaction, mass is neither created nor destroyed; it is conserved.  Mass reactants = Mass products  Law of Spontaneous generation

3.3 – Mixtures of Matter  A mixture is a physical blend of two or more substances in which each substance retains its individual chemical properties.  What is the difference between heterogenous and homogenous mixtures?  Heterogeneous mixture – mixture that does not blend smoothly throughout and in which the individual substances remain distinct.  Homogenous mixture – mixture that has constant composition throughout; it always has a single phase.  How many phases does a solution have?  Solutions = homogeneous mixtures

Separating Mixtures  What are six methods of separating mixtures?  Filtration  Technique that uses a porous barrier to separate a solid from a liquid.  Distillation  Physical separation technique that is based on differences in the boiling points of the substances involved.  Crystallization  Separation technique that results in the formation of pure solid particles of a substance from a solution containing the dissolved substance.

Separating Mixtures  Sublimation  Process during which a solid changes to vapor without melting.  Chromatography  Technique that separates the components of a mixture dissolved in either a gas or a liquid based on the ability of each component to travel or to be drawn across the surface of a fixed substrate.  Magnets  Technique that separates the components of a mixture based on the magnetic properties of the components.  How would you separate a mixture of sand, salt, iron filings, and water?

3.4 - Elements and Compounds  Elements are pure substances that cannot be separated into simpler substances by physical or chemical means.  The periodic table organizes the elements into a grid of horizontal rows (periods) and vertical columns (groups or families).  Compounds are substances made up of two or more different elements that are combined chemically.  What are “chemical means” of separating compounds?

Mass Number  Adds the total number of protons and neutrons together.  MASS NUMBER DOES NOT EQUAL ATOMIC MASS!!!!!!!!!  Mass number is not on the periodic table.

Mass Number

Law of Definite Proportions  masses of the same elements are always in the same proportions in any chemical compound  some compounds contain the same elements but have different physical/chemical properties  Sucrose = 42.2% Carbon, 6.5% Hydrogen, 51.3% Oxygen  % by mass = Mass of element x 100 Mass of compound

Law of Multiple Proportions  When different compounds are formed by a combination of the same elements, different masses of one element combine with the same fixed mass of the other element in a ratio of small whole numbers.  compares two different compounds containing the same elements  Water (H 2 O) and hydrogen peroxide (H 2 O 2 )