Matter Part I C. Smith Fall 2013
Ch. 2 Matter and Change. Anything that has mass and takes up space. Energy is NOT matter
Ch. 2 Matter and Change. Properties of Matter Matter is any substance that has mass and takes up space. All objects contain matter. Matter is classified in two forms: Heterogeneous material Homogeneous material. Matter is divided into 3 types: Elements Compounds Mixtures
Mixtures- Classifying MixturesHeterogeneous Material Heterogeneous means more than one type of substance. Heterogeneous matter exists in the form of mixtures. A mixture is matter that consists of two or more different materials. Mixtures can be separated by physical means. Mixtures have phases, which are any region with a uniform set of properties. The boundaries between these phases are called interfaces.
HomogeneousMaterial Homogeneous means only one type of a substance. Homogeneous matter is matter that is uniformly mixed and cannot be separated easily. Homogeneous matter exist in several forms: Pure Substances- Elements & Compounds Solutions Solutions consist of solute (dissolved material) and solvent (dissolving material). Solute particles are very small and are scattered in the solvent and appear as uniform. Solutions are not always liquid.
Elements and CompoundsDistinguishing Between Elements and Compounds There are two types of pure substances.Elements Compounds. Substances made of only one kind of atom are called elements. Substances made of more than one kind of substances are called compounds.
Elements: SIMPLIST KIND OF MATTER Elements are the building blocks for all other substances. Cannot be broken down into simpler substances. All atoms of an element have the same number of protons. There are 109 of these currently listed and named on the Periodic Table
Elements: 4 Basic Types of Elements Metals: found on the left and center of the Table of Elements Non-metals: found on the right side of the Table of Elements Metalloids: found along the stair-step line Synthetic: made in the laboratory and not yet found in nature – many of the Actinide and Lanthanide series and very large # elements.
Diatomic Elements – Nonmetals that come asmolecules • 7 Elements are di- (2) atomic (atoms) • The easy way to remember them is by the name • Br2 I2 N2 Cl2 H2 O2 F2
Compounds • Compound- Made of molecules- two or more atoms • can be separated into simpler substances only by chemical means. • Molecules are the smallest particle of a compound that retains its properties and it is composed of 2 or more atoms. • When they are broken down, the pieces have completely different properties than the compound.
A chemical formula is a combination of symbols that represents the composition of a compound. • A formula shows two things: • 1.The elements present in the compound2. The relative number of atoms of each element in the compound. • Example H2O • Formulas often contain numerals to indicate the ratio of elements in the compound. • The numbers used in the formula are called subscripts. Symbols and Formulas Each element is represented by one- or two- letter chemical symbol. The symbols for most elements consist of the first one or two letters of the element’s name.
Phases of Matter Gases Gas particles are independent of each other and move in a straight line. Change in direction occurs only with collisions. Gases assume the shape and volume of their container.
Phases of Matter Liquids • Liquid particles do not act independently of each other - motion is limited. • Liquid particle slips by each other because the particles have vibratory type of motion. • The particles still travel in a straight-line path between collision. • Liquids have definitive volume and assume the shape of their container.
Phases of Matter Solids • Solid particles occupy a regularly fixed position in relation to surrounding particles. • Solid particle appears to vibrate around a fixed point. • Particles are closely packed and travel a distance equal to only a fraction of their diameter before colliding. • Solid particles are arranged in a definite pattern and have definite shape and volume.
Phases of Matter Plasma Plasma is a high energy electrically charged mixture of ions and electrons. Particles that have been ionized (charged) There exist at extremely high temperatures. Exist at naturally (stars) or man-made (neon signs). While plasma is the most abundant phase of matter in the universe, on earth it only occurs in a few limited places. Bose-Einstein condensate Extremely dense form of matter. Particle motion slowed down by decreasing temperature to cease motion. Consider to be super unexcited and super cold (approaching absolute zero, – 273K)
Phase Changes Physical changes are changes in the form of a substance but not in the substance. The substance remains the same after the change but appears different. (Phase change) Physical changes can be reversible. Examples of phase changes Melting Freezing Boiling/Vaporization Condensation Evaporation Sublimation
Physical Properties Physical properties are two types:Extensive properties& Intensive properties. • Intensive properties are used to identify a substance. • Density • Color • Crystalline shape • Melting and Boiling point • Refractive index Extensive properties are properties that depend on the amount of matter present. Mass Length Volume
Chemical ReactionsChanging Reactants to Products • There are several examples of chemical changes • Burning • Digestion • Fermenting • Corrosion Chemical changes are changes in which a new substance with different characteristics from the original substance is produced. Chemical changes are not reversible.
Chemical ReactionsChanging Reactants to Products • Chemical properties describe the reaction of a substance with other material or the reaction within the substance itself. • Lack of chemical reactivity is also important. • The evidence of a chemical reaction • Color Change • Formation of a gas • Temperatures change. • Odor • Precipitate
Conservation of Mass During a chemical reaction, the quantity of matter is unchanged. The mass of products is always equal to the mass of reactants. The same can be said for physical changes. This is known as the Law of Conservation of Mass.The law states that mass can neither be created nor destroyed, it is conserved. Some of the mass can be in the form of energy or a gas.
Matter Can be separated physically Cannot be separated physically Mixture Pure Substance Cannot see the parts Can be separated chemically Can see the parts Cannot be separated Heterogeneous Mixture Homogeneous Mixture Compound Element suspension colloid Most impure Most pure
Classify the following slide using these five classifications:- Non-matter- Heterogeneous Mixture- Homogeneous Mixture- Compound- Element
Helium He Diamond C Electricity Bronze Cu + Sn Italian Dressing Heat Light Steel Fe + C Air N2 + O2 + Ar + CO2 Mercury Hg Cookie Salt Water H2O + NaCl Water H2O Iron Fe Carbon Dioxide CO2
Work Cited • Nichols, Nancy : Klein Collins Science specialist (Ret.) • Textbook: Chemistry , Wilbraham, Staley, Matta, Waterman; Addison-Wesley