Matter and Change. Chapter two coggle (States of matter (Three states of…
Matter and Change. Chapter two coggle
properties of matter
Extensive property: A property that depends on the amount of matter in a sample. ex) mass or volume
Properties used to describe matter can be classified as intensive or extensive.
Intensive property:A property that depends on the type of matter in a sample, not the amount of matter. ex) color, temperature.
Volume: The volume of an object is a measure of space occupied by the object.
Every sample of a given substance has identical intensive property because every sample has the same composition.
Physical property: A quality or condition of a substance that can be observed or measured without changing the subtances compostion.
States of matter
Three states of matter are solid, liquid and gas
Solids: A form of matter that has a define shape and volume. The shape of a solid doesn't depend on the shape of its container. Not easily compressed, solids only expand only slightly when heated.
Liquid: A form of matter that has an indefinite shape, flows yet has a fixed volume. Liquids are almost incomprehensible but they tend to expand when sightly heated.
Gases: A form of matter that takes both shape and volume of its container. The particles in a gas are usually much further apart than particles in water because of space between the particles, gases are easily compressed into a smaller volume.
Vapor: describes the gaseous state of a substance that is generally a liquid or a solid at room temperature, as in water vapor.
Physical change: During a physical change, some properties of a material change, but the composition of the material does not change.
Physical changes can be classified as reversible of irreversible.
Examples of words to describe physical changes: Boil, freeze, melt and condense.
Classifying mixtures: Based on the distribution of their components, mixtures can be classified as heterogeneous mixtures or homogeneous mixtures.
Mixture: A physical blend of two or more components.
Heterogeneous mixtures: A mixture in which the composition is not uniform throughout.
Homogeneous mixtures: A mixture in which the composition is uniform throughout.
Solution: another name for a homogeneous mixture
Phase: A term that is used to describe any part of a sample with uniform composition and properties.
Separating mixtures: Differences in physical properties can be used to separate mixtures.
Filtration: The process that separates a solid from the liquid in a heterogeneous mixture. Example) noodles in a strainer.
Distillation: During distillation a liquid is being boiled to produce a vapor that is then condensed into a liquid.
Distinguishing Elements and Compounds: Compounds can be broken down into simpler substances by chemical means, but elements can not.
Breaking down compounds: Physical methods that are used to separate mixtures can not be used to breakdown a compound into simpler substances.
Element: simplest form of matter that has a unique set of properties.
Compound: A substance that contains two or more elements chemically combined in a fixed proportion.
Chemical change: A change that produces matter with a different composition than the original matter.
Distinguishing Substances and Mixtures: If the composition of a material is fixed, the material is a substance, if the composition of a matter may vary, the material is a mixture.
Symbols and Formulas
Chemist use chemical symbols to represent elements, and chemical formulas to represent compounds.
The symbols used today were invented by a Swedish chemist, jons Jacob Berzelius(1779-1848). He based his symbols on the Latin names of elements.
Each element is represented by one or two-letter chemical symbol. The first letter of a chemical symbol is always capitalized when and if a second letter is used it is lowercase.
During a chemical change, the composition of matter always changes.
Chemical property: The ability of a substance to undergo a specific chemical change.
A chemical change is also called a chemical reaction. One or more substances change into one or more new substances during a chemical reaction. A substance present at the start of the reaction is a reactant. A substance produced in the reaction is the product.
Recognizing Chemical Changes.
Possible clues to chemical change include a transfer of enrgy, a change in color, the production of gas, or the formation of a precipitate.
Precipitate: A solid that forms and settles out of a liquid mixture.
Conservation Of Mass
During any chemical reaction, the mass of the products is always equal to the mass of the reactants.
The Law Of Conservation of mass: States that in any physical change or chemical reaction, mass is conserved. Mass is either created nor destroyed. The conservation of mass is more easily observed when a change occurs is a closed container.