CHAPTER 3 Matter and Change

Section 3.1 Properties of Matter Matter is anything that has mass and takes up space. Matter is everything around us. Matter with a uniform and unchanging composition is a substance.

States of Matter The physical forms of matter, either solid, liquid, or gas, are called the states of matter.states of matter Solids are a form of matter that have their own definite shape and volume.Solids Liquids are a form of matter that have a definite volume but take the shape of the container.Liquids

Gases have no definite shape or volume. They expand to fill their container.Gases Vapor refers to the gaseous state of a substance that is a solid or liquid at room temperature.Vapor

Physical Properties of Matter A physical property is a characteristic that can be observed or measured without changing the sample’s composition.physical property

Extensive properties are dependent on the amount of substance present.Extensive properties Examples??? Intensive properties are independent of the amount of substance present.Intensive properties Examples???

Chemical Properties of Matter The ability of a substance to combine with or change into one or more other substances is called a chemical property.chemical property –Iron forming rust –Copper turning green in the air

A substance can change form– both physically & chemically!!! Chemical properties can change with specific environmental conditions, such as temperature and pressure.

Section 3.2 Changes in Matter Physical Changes… A change that alters a substance without changing its composition is known as a physical change.physical change

Phase changes are physical changes!!! Melting – s to l Freezing – l to s Evaporating/Boiling – l to g Condensation – g to l Sublimation – s to g Deposition – g to s

Chemical Changes… A change that involves one or more substances turning into new substances is called a chemical change. chemical change Decomposing, rusting, exploding, burning, or oxidizing are all terms that describe chemical changes.

A chemical reaction always produces a change in properties!!! Indicators of Chemical Change: color change temperature change odor produced gas or precipitate (solid) formed

Our 1 st Scientific Law this year… The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction, it is conserved.law of conservation of mass The mass of the reactants equals the mass of the products. mass reactants = mass products Lavoisier, late 1700’s

Section 3.3 Mixtures of Matter Mixtures… A mixture is a combination of two or more pure substances where each substance keeps its individual chemical properties.mixture A homogenous mixture is a mixture where the composition is constant throughout. You can see only one phase present in the mixture.homogenous mixture

Homogeneous mixtures are also called solutions. solutions Solutions may be solids, liquids, or gases. Examples: brass, salt water, and air.

A heterogeneous mixture is a mixture where the individual substances remain distinct. You can see two or more distinct phases present in the mixture.heterogeneous mixture Examples: oil and water, dirt, and granite.

Separating Mixtures Filtration is a technique that uses a porous barrier to separate a solid from a liquid in a heterogeneous mixture.Filtration Distillation is a separation technique for homogeneous mixtures that is based on the differences in boiling points of substances.Distillation Ex: distilling salt water to get pure drinking water

Crystallization is a separation technique for homogenous mixtures that results in the formation of pure solid particles from a solution containing the dissolved substance.Crystallization Ex: making rock candy

Sublimation is the process of a solid changing directly to a gas, which can be used to separate mixtures of solids when one sublimates and the other does not.Sublimation Chromatography is a technique that separates the components of a mixture on the basis of tendency of each to travel across the surface of another material.Chromatography Ex: separating dyes in ink

Section 3.4 Elements and Compounds Elements… An element is a pure substance that cannot be separated into simpler substances by physical or chemical means.element 92 elements occur naturally on Earth. Each element has a unique name and a one, two, or three-letter symbol.

The periodic table organizes the elements into a grid of horizontal rows called periods and vertical columns called groups.periodic table

Compounds… A compound is a made up of two or more elements combined chemically.compound Most of the matter in the universe exists as compounds. Table salt, NaCl, and water, H 2 O, are compounds. Sodium Chloride Formation

Elements can never be separated. Compounds can be broken into components by chemical means. Ex: electrolysis of water producing hydrogen gas and oxygen gas Electrolysis of Water The properties of a compound are different from its component elements.

All matter can be classified as …

Law of Definite Proportions The law of definite proportions states that a compound is always composed of the same elements in the same proportion by mass, no matter how large or small the sample.law of definite proportions The relative amounts are expressed as percent by mass, the ratio of the mass of each element to the total mass of the compound expressed as a percentage.percent by mass

This table demonstrates that the percentages of elements in sucrose remain the same despite differences in sample amount!!!

Law of Multiple Proportions The law of multiple proportions states that when different compounds are formed by a combination of the same elements, different masses of one element combine with the same relative mass of the other element in whole number ratios.law of multiple proportions –H 2 O 2 (hydrogen peroxide) and H 2 O –Copper (I) chloride (CuCl) and Copper (II) chloride (CuCl 2 )

Copper (I) Chloride and Copper (II) Chloride…