Matter - anything that has mass and takes up space

Matter- anything that has mass and takes up space Things that are not matter: Forces Energy Magnetic, electric, and gravitational fields Vacuum

What is Mass? Amount of matter an object has It is not the same as weight Weight depends on gravity. It can change depending on where you are, but mass does not change

What instrument can we use to measure Mass? Balances- triple beam, analytical, pan balance What are the units for mass? Kilogram is the SI unit, but we usually use grams in class

Physical Properties: These can be observed without changing the composition of the substance color mass boiling point melting point density

Melting Point The temperature at which a substance changes from a solid to a liquid What is the point that a substance changes from a liquid to a solid called? Freezing Point Are these points the same? YES The name depends on the direction of the change

Boiling Point The temperature at which the vapor pressure of a liquid is just equal to the external pressure on the liquid Density The ratio of mass and volume

Volume- the amount of space matter takes up Units used: Solids: Liquids: m3 Liters or any conversions of m

There is a connection between the solid and the liquid measure 1 cm3 = 1 mL How is this helpful in getting the volume of an irregular shaped object?

Instruments used to obtain volume: Ruler Beakers Graduated cylinders

States of Matter Solids Particles are close together Definite shape and volume Slight expansion when heated Not compressible

Liquids Particles close together, but they move past each other to allow then to flow Take the shape of container definite volume Tend to expand when heated Almost incompressible

Water A special liquid that expands when it freezes This allows ice to float since it becomes less dense than the liquid form- fish live in the winter

Gases Particles are spaced far apart Take shape and size of container Easily compressible Vapor- a gaseous state of a substance that is a solid or liquid at room temperature

Physical Changes of Matter Changes that do not change the composition of the substance bending cutting crushing Changing the state of matter

Mixtures Physical blend of 2 or more substances Composition may vary- the samples may not be the same Examples: tea, salt water, alloys

Types of Mixtures Heterogeneous These are not uniform in composition Individual particles or areas can be seen Examples: salad, sand in water

Homogeneous Uniform composition- they look the same throughout Also known as solutions which are made by dissolving a solute in a solvent Examples: tea, coffee, salt water

Phases: These are uniform parts of a mixture Homogeneous solutions have 1phase Heterogeneous mixtures have 2 or more phases, each phase with a distinct area

Common Solutions: Gas in Gas: air- composed of CO2, O2, N2, and other gases Liquid in Gas: water vapor in air, moisture Gas in Liquid: Soda Liquid in Liquid: vinegar- acetic acid in water Solid in Liquid: salt water Solid in Solid: alloys- bronze, brass, steel

Mixtures are physically combined, so they can be physically separated Distillation: separation of 2 or more liquids based on boiling points Magnets: magnet solid from nonmagnetic solid Chromatography: separate liquids based on their solubilities Filtration: solid from a liquid Decanting: pouring off a liquid from a solid

Centrifuge: separation of solids from a liquid by using an instrument that spins very fast causing the solid to move to the bottom of the tube Done in medical labs, biology Evaporation: liquid in a solution is evaporated off leaving behind a solid This is also called recrystallization

What is a Substance? Matter with uniform and definite composition All examples of a substance have the exact same composition Examples: water, table salt, carbon dioxide

Types of Substances: Elements: Cannot be broken into smaller substances by chemical means Found on the Periodic Table Represented using 1 or 2 letter symbols If 2 letters are used, the first is capitalized and the second is lowercase Example: O, Cu, Co

Compounds: 2 or more elements chemically combined These are separated by chemical means- heating and electricity The properties of the compound are different from the elements that make up the compound Example: Sugar

Represented with formulas that show how many of each element there are in 1 molecule of the compound Example: Table sugar C12H22O11 has 12 atoms of carbon, 22 atoms of hydrogen and 11 atoms of oxygen

Chemical Properties The ability of a substance to react with another substance to form a new substance OR the inability of a substance to react with another substance to form a new substance Example: Iron reacts with oxygen to form rust, but aluminum does not react with oxygen to form rust

Chemical Changes: Properties of the substance changes When a chemical change occurs, you cannot get the original substances back by any physical means Burning Cooking Reacting with another element or compound

Chemical Reactions When 1 or more substances change into a new substance How do you know a chemical reaction took place? Change in Temperature Change in color or odor Gas production- bubbles Solid production- precipitate

Representing Reactions: Reactants Products yields What goes into reaction The new substance Example: 2NaCl 2Na + Cl2 20 g + 20 g = 40 g

Conservation of Mass Mass cannot be created or destroyed, so the amount that goes into the reaction must come out That is why you have a balanced equation That is why the mass of the reactants is equal to the mass of the products

Matter - anything that has mass and takes up space