All About Matter SC2. Obtain, evaluate, and communicate information about the chemical and physical properties of matter resulting from the ability of atoms to form bonds. a. Plan and carry out an investigation to gather evidence to compare the physical and chemical properties at the macroscopic scale to infer the strength of intermolecular and intramolecular forces. b. Construct an argument by applying principles of inter- and intra- molecular forces to identify substances based on chemical and physical properties. SC3. Obtain, evaluate, and communicate information about how the Law of Conservation of Matter is used to determine chemical composition in compounds and chemical reactions. b. Plan and carry out an investigation to determine that a new chemical has been formed by identifying indicators of a chemical reaction (e.g., precipitate formation, gas evolution, color change, water production, and changes in energy to the system).

What is matter? Matter is the “stuff” that the universe is made of Matter has mass and volume MASS: measurement of the amount of matter VOLUME: measurement of the amount of space that matter takes up

Where did it all come from? Nobody knows the answer to this question – YET! (but we are close…) The original composition of matter consisted of atoms of hydrogen (99% of the universe is still made of this) All matter that exists today results from the process of NUCLEAR FUSION of smaller atoms combining together to form larger atoms.

KINETIC MOLECULAR THEORY OF MATTER Matter is made up of very small particles which are in continuous random motion.

STATES OF MATTER Also referred to as “phases” Based on particle arrangement Based on energy of particles Based on distance between particles

SOLID Particles of solids are tightly packed, vibrating about a fixed position. Solids have a definite shape and a definite volume. Incompressible, have low kinetic energy and motion Intermolecular forces are strong

LIQUID Particles of liquids are tightly packed, but they are far enough apart to slide over one another. Liquids have an indefinite shape and a definite volume. Incompressible, have moderate kinetic energy and motion Intermolecular forces are weaker

GAS Particles of gases are very far apart and move freely. Gases have an indefinite shape and an indefinite volume. Highly compressible, have high kinetic energy and motion Virtually no intermolecular forces A vapor is what you call the gaseous state of something that is normally a solid or liquid at room temperature.

PLASMA Ionized gas Very good electrical conductor and is affected by magnetic fields Plasmas, like gases, have an indefinite shape and an indefinite volume. Plasma is the most common state of matter in the universe

States of Matter SOLID LIQUID GAS PLASMA SHAPE SIZE PARTICLES Definite Indefinite SIZE PARTICLES Tightly packed Loosely arranged Highly disordered Disordered and ionized STRUCTURE Rigid Fluid SPECIAL TRAITS? Resistant to changes in form Surface tension Highly compressible Electrically conductive EXAMPLE Sugar Water Air Lightning

PHASE CHANGES +Heat SOLID to LIQUID LIQUID to GAS SOLID to GAS Melting Vaporization Boiling (from within) Evaporation (at the surface) Sublimation

PHASE CHANGES -Heat GAS to LIQUID LIQUID to SOLID GAS to SOLID Condensation Freezing Deposition

PHASE DIAGRAM

Heat in… Heat out… ENDOTHERMIC EXOTHERMIC Term for any change in which heat is absorbed These tend to feel cold because they absorb heat from our skin Heat out… EXOTHERMIC Term for any change in which heat is released These tend to feel warm because they release heat to our skin

HEATING/COOLING CURVE

Types of Matter MATTER PURE SUBSTANCES MIXTURES ELEMENTS COMPOUNDS HOMOGENEOUS HETEROGENEOUS

Types of Matter PURE SUBSTANCES Have uniform and unchanging composition Cannot be separated mechanically Requires the substance to be changed chemically into other substances Electrolysis

Pure Substances ELEMENT: cannot be separated into simpler substances carbon, aluminum, oxygen (anything on the Periodic Table)

Pure Substances COMPOUND can be broken down chemically into elements electrolysis salt, sugar, water (anything that has a specific formula)

Types of Matter MIXTURES Have non-uniform or varying composition Physical combination of substances, so they can be separated mechanically Filtration, distillation, chromatography

DISTILLATION FILTRATION CHROMATOGRAPHY

Mixtures HOMOGENEOUS Composition appears uniform throughout; individual substances indistinct Commonly referred to as solutions KoolAid, air, alloys

Mixtures HETEROGENEOUS Does not blend smoothly; individual substances remain distinct cereal, pizza, iced tea

Mixtures HETEROGENEOUS Suspensions have particles that will settle Muddy water, salad dressing Colloids have particles that will scatter light Milk, gels, aerosols

Properties of Matter PHYSICAL properties are characteristics that can be observed or measured without changing the sample’s composition (what it’s made of)

Physical Properties EXTENSIVE: dependent on the amount of matter present mass, volume, length, molar amount INTENSIVE: independent of the amount of matter present density, color, odor, state

Properties of Matter CHEMICAL properties are characteristics that can only be observed by changing a sample’s identity flammability, reactivity, toxicity

Changes in Matter PHYSICAL changes alter a material’s form without changing the composition Cutting paper Melting ice Boiling water

Changes in Matter CHEMICAL changes involve substances combining or breaking up to form new substances in chemical reactions Burning paper Rotting food Rusting metal

Evidence of a Chemical Change So how do you know if a chemical change has occurred? You should observe at least one of the following characteristics: Precipitation (two liquids mix and form a solid) Gas evolution (fizzing, bubbling, or producing odors) Color change (colors appear, disappear, or change) Water production (solids can appear to liquefy) Changes in energy (gets cold or warm, produces light or sound)

It’s the LAW! By carefully measuring the masses of substances before and after chemical reactions, it was observed that the total mass involved in the reactions remained constant (reactant mass = product mass) The Law of Conservation of Matter (Mass) states that mass is neither created nor destroyed during a chemical reaction – it is conserved.