Presentation on theme: "Unit 2: Study of Matter You may already know why ice floats. Ironically, if the ice was “dry,” it would sink. What explains that?"— Presentation transcript:
Unit 2: Study of Matter You may already know why ice floats. Ironically, if the ice was “dry,” it would sink. What explains that?
Unit 2 Objectives Definitions: matter, element, compound, mixture, (chemical) symbol, heterogeneous, homogeneous, metal, nonmetal, metalloid, physical change, chemical change, nuclear change, Laws of conservation, exothermic, endothermic, Kinetic Molecular Theory, real gas, ‘ideal’ gas, change of state, phase diagram, triple point, critical point. Differentiate between elements, compounds, and mixtures. Arrange a matter hierarchy. Identify chemical symbols for elements. Separate mixtures physically. Differentiate between hetero- and homogeneous mixtures. Sepearate metallic, nonmetallic, and metalloid elements. Determine the physical and chemical properties of a substance. Distinguish chemical and physical properties from chemical and physical changes. Perform calculations using the Law of Definite Composition.
Unit 2 Objectives Pt.2 The Kinetic Molecular Theory (KMT) is based on the idea that particles in matter are always in motion. The KMT can be applied to describe properties of solids, liquids, and gases. Boiling, melting, freezing are among the physical processes that can alter a substances state. How to interpret a phase diagram. Identify the triple point and critical point. (EFS D4) To use systems thinking and systems tools to identify patterns, impacts, and relationships between a product’s life cycle and the health of the system as a whole. Embed their understanding of the Materials cycle principle in their work. (EFS D5) Articulate how human choices regarding consumption, production, distribution, and disposal of material goods affect our ability to thrive over time.
Essential Questions How do the types of substances – elements and compounds – differ? How do the states of matter differ according to the Kinetic Molecular Theory? GUIDING QUESTIONS: What are the characteristics of elements and compounds? Why can’t a compound be separated by physical means? What are the different categories of elements? How do the properties of the general types of elements compare? What are the characteristics of mixtures? What physical means are used to separate mixtures? What are the distinctions between matter and energy? Why are chemical and physical properties important? What is the importance of the Laws of Conservation of Matter and Energy and Definite Composition? How are physical, chemical, and nuclear changes distinguished? What is the Kinetic Molecular Theory of Matter? How can the theory be used to describe matter? How does a ‘real’ gas differ from an ‘ideal’ gas? What is a change of state? What occurs when a substance undergoes a change of state? What is a phase diagram and how is it interpreted?
Your Take How many atoms are in the body?(P3) What is plasma? What is “dark” matter? How do we measure how much matter is present? How are they able to organize the elements onto a table? (P5) How is aluminum made? Are there more than the four common states of matter? Can you turn lead into gold by firing other atoms at it? (P7) How do they find new elements? Why could lead be in our water? Cornstarch + Water = ??? Where did the names of elements come from?
Castagno Chemistry Challenge II Rules: ◦ 1) Do NOT help anyone else. ◦ 2) You have a maximum of 10 minutes to complete the challenge. ◦ 3) Credit only goes to COMPLETELY correct answers ◦ 1 st – 2pts, 2 nd – 1pt, 3 rd – 0pts, 4 th – 0pts ◦ Questions?
The Challenge Organize the matter hierarchy.matter hierarchy
What Is Matter? As defined in Unit 1, matter is “anything that has mass and occupies space (volume)” There are 3 visible in this picture, sort of.
Classification of Matter Can it be separated? Pure substances Mixtures Can it be decomposed by ordinary chemical means? Is the composition uniform? CompoundsElements Heterogeneous mixtures Homogeneous Mixtures Forward
Mixtures A mixture is a combination of two or more substances. Substances can be elements or compounds. Mixture can be easy to identify or not.
Mixtures II – Separation Anxiety Mixtures can be separated physically ◦ Filters – based on particle size ◦ Distillation – based on boiling point ◦ Centrifuge – based on density Back
Homogeneous Mixtures Uniformity throughout the entire mixture. Back
Heterogeneous Mixtures Easy to identify different materials within the sample. ◦ Different colors stand out ◦ Different densities settle into layers Back
Pure Substances FIXED composition ◦ Each sample (like salt) has the same Composition (make-up) Characteristics (color, density, etc.) Back
Compounds Composed of chemically bonded atoms of different elements ◦ Individual Molecules (water) ◦ Ionic crystals (salt) Back
Elements (I) A pure substance composed of atoms that can not be broken down into simpler, stable substances.
Elements (II) – Symbols Every element is abbreviated with a symbol ◦ Saves space on a periodic table ◦ Makes writing formulas much easier Some are common or make sense ◦ C – carbon ◦ Al – aluminum But some seem very out of place…
Elements (III) – Symbols (II) Challenge #2 – Thou fhouldeth puteth thyne notebookf away. Medieval Matching Game
Elements (IV) - Identification Challenge #3 – Notebooks away! ◦ The rare back-to-back challenge! Can you identify the elements as metallic, nonmetallic, metalloid, or the single, very special, undecided one?identify the elements
Elements Examples 1) Worlds largest gold bar, 250kg ◦ Estimated worth (9/30/13): $10,663,679 ($42.53/g) 2) The Hope Diamond (carbon) ◦ Estimated worth: $350,000,000 ($38,461,538/g) 3) Chunks of Boron ◦ Estimated worth: $11.14/g (pure)
Elements (V) - Metals As challenge #3 revealed, the majority of elements are metallic. Typical properties associated with them ◦ Conductors of heat and electricity ◦ Malleable (sheets, foils) ◦ Ductile (wires)
Elements (VI) – Nonmetals The second largest category of elements are nonmetallic “Opposite” properties of the metals ◦ Poor conductors of heat and electricity ◦ Brittle Typically break instead of flatten into sheets or wires Of course, most nonmetals are gases so how can you flatten a gas anyway?
Elements (VIII) – Metalloids Just a few elements, located on the “staircase,” have intermediate properties. ◦ Less malleable than metals ◦ Less brittle than nonmetals ◦ Semiconductors Not as conductive as a metal, more conductive than a nonmetal
Elements (IX) – Specialty Hydrogen! ◦ Typically non- metallic with all associated properties ◦ However, it is believed to behave as a metal inside the gas giants Jupiter and Saturn. ◦ This metallic form helps explain the massive magnetic fields those planets have. Back
Check Yourself Challenge #4 - Notebooks away! Class Quiz
The Grand Unified States of Matter The extremely rare double back- to-back Challenge #5 – Notebooks out! Describe as much as possible of the 4 examples of matter located on the desks in the classroom.
States of Matter So we know there are 4 states of matter but do any others exist? Fundamental (4) ◦ Solid, liquid, gas, plasma Non-classical (8*) ◦ Glass, plastic crystal, liquid crystal, magnetically ordered (ferro-, antiferro, ferri- magnet), Copolymers, Quantum spin liquids Low-Temperature States (7*) ◦ Superfluid, Bose-Einstein Condensate, Fermionic condensate, Rydberg molecule, Quantum Hall State, Strange matter (quark), Photonic matter (formed September 2013) High Energy States (3*) ◦ Quark-gluon plasma, color-glass condensate, gravitational singularity (VERY high energy) Other proposed states (6*) ◦ Degenerate matter, supersolid, string-net liquid, superglass, dark matter, equilibrium gel Total: 4 + 8 + 7 + 3 + 6 = 28 (source: wikipedia…)
Kinetic Molecular Theory Every state of matter, from the “normal” to the strange, have one thing in common: Manner of definition Each state of matter is defined by the movement of the particles within.
Kinetic Molecular Theory II The KMT is what describes the movement It can be applied specifically to each state of matter
Gas The Kinetic Molecular Theory has 5 distinct points for gases ◦ 1) Individual particles are far apart relative to their size ◦ 2) Collisions between particles and containers are elastic (no energy loss) ◦ 3) Particles are in constant motion ◦ 4) No forces of attraction between particles ◦ 5) Temperature of the gas depends on the average kinetic energy of the particles
Gas II Steam and smoke are good examples. The KMT describes ◦ 1) Indefinite shape (only containers define the shape) ◦ 2) Indefinite volume (any amount “fills” a container)
Gas III 3) Low density & 4) High compressibility ◦ Gas particles are very far apart 5) Fluidity ◦ Gas particles always moving
Gas IV 6) Expansion (Gas tanks) ◦ Volume can grow 7) Diffusion (Scented candle) ◦ Spreading through an area 8) Effusion (flat tire) ◦ Escape tiny opening
Solid What explains solids always keeping their shape? ◦ 1) Specific, repeating pattern of atom arrangement ◦ 2) Particles vibrate in position
Solid II Lack of movement explains ◦ 1) Definite volume ◦ 2) Definite shape ◦ 3) Incompressibility Close arrangement results in ◦ 4) Typically high density (solid v liquid v gas of the same substance)
Liquid Unlike solids, liquids particles are not in fixed positions ◦ They do remain fairly close together This allows a liquid to take any shape
Liquid II Shifting positions explains ◦ Fluidity, Indefinite shape Closeness of particles means ◦ Definite volume ◦ Still fairly dense (usually less so than the solid, water is an exception) ◦ Relatively incompressible
Plasma Typical properties of a gas except most/all particles are ionized (charged) Extremely common, albeit temporarily seen on Earth
St. Elmo’s Fire* A weather phenomenon typically produced during thunderstorms. There needs to be a sustained imbalance Of electric energy often found in places we would consider a ‘lightning rod.’ When a limit is, reached, the energy is discharged into the glow of ‘fire.’
STOP! In the name of conservation! Challenge #6 – Notebooks closed! There are two major “laws” (among many) that we encounter in this class. What are they?
Conservation of Matter In chemical reactions, matter cannot be created nor destroyed. 20g of reactants will form a minimum and maximum of 20g product.
Conservation of Energy The amount of energy present in a system will remain constant. The energy present could cause a change, such as melting of an ice cube, but overall energy is conserved.
Ch-ch-changes! Challenge #7 – Notebooks away! There are 6 changes of state between solid, liquid, and gas. Name the transition AND the associated change (ie: L -> G)
Properties The characteristics of substances are known as “properties” Physical Chemical Forward
Physical Properties Can be described by sight or feel… ◦ Color ◦ Texture …or measured without changing the substance’s identity ◦ Melting/Freezing Point, ◦ Boiling Point ◦ Density
Physical Changes When a substance changes form but not identity ◦ Crush ◦ Tear ◦ Rip ◦ Boil ◦ Freeze ◦ Condense ◦ Melt ◦ Sublimate ◦ Deposit Back
Chemical Properties Ability of a substance to undergo change to form a new substance ◦ Aka identity changes Cannot be determined by simply “looking” at the substance
Chemical Changes The substance undergoing a transformation into a new substance(s) Adding sodium to water causes this Back
Physical and Chemical Change Physical Change ◦ The substance changes form Melt, Boil, Freeze, Condense, Sublimate, Deposit, Crushed, Torn, Smashed Chemical Change ◦ The substance changes identity React, Burn, Oxidize, Reduce
Phase Diagrams Challenge #8.1 – Notebooks away! Describe what is happening from ◦ A to B ◦ B to C ◦ C to D ◦ D to E ◦ E to F
Phase Diagrams Challenge Answers 8.1 ◦ A to B = solid heating ◦ B to C = melting ◦ C to D = liquid heating ◦ D to E = boiling ◦ E to F = vapor heating 8.2 ◦ A to B = vapor cooling ◦ B to C = condensing ◦ C to D = liquid cooling ◦ D to E = freezing ◦ E to F = solid cooling
Phase Diagram - Cooling A cool curve is a graph which shows the temperature of a substance decreasing over time. Phase changes that occur during this process are ◦ Condensing ◦ Freezing
Phase Diagram – Cooling II Phase changes occur during segments of no temperature change FREEZING CONDENSING Solid Liquid Gas
Phase Diagram – Cooling III Condensing (Gas to Liquid) ◦ The process of a gas becoming a liquid ◦ Requires a LOSS of energy (cooling) Freezing (Liquid to Solid) ◦ The process of a liquid becoming a solid ◦ Requires a LOSS of energy (cooling)
Phase Diagram - Heating A heating curve is a graph which shows the temperature of a substance increasing over time. Phase changes that occur during this process are ◦ Melting ◦ Boiling
Phase Diagram – Heating II Phase changes occur during segments of no temperature change MELTING BOILING Solid Liquid Gas
Phase Diagram – Heating III Melting (Solid to Liquid) ◦ The process of a solid becoming a liquid ◦ Requires a GAIN of energy (heating) Boiling (Liquid to Gas) ◦ The process of a liquid becoming a gas ◦ Requires a GAIN of energy (heating)
Phase Diagram - Review Whether heating (L) or cooling (R), CHANGES IN STATE occur on the FLAT LINES ◦ Boiling/Condensing – higher ◦ Melting/Freezing – lower BC MF
Phase Diagram - Y Challenge #9 – Notebooks away!
Phase Diagram - Y Label ◦ X, Y, Z, D, and E ◦ X Z? ◦ Z X? ◦ X Y? ◦ Y X? ◦ Y Z? ◦ Z Y?
Phase Diagram - Y Label ◦ X = Solid ◦ Y = Liquid ◦ Z = Gas ◦ D = Triple Point ◦ E = Critical Point ◦ X Z = sublimation ◦ Z X = deposition ◦ X Y = melting ◦ Y X = freezing ◦ Y Z = boiling ◦ Z Y = condensation
Phase Diagram – Y II Area “X” is always a solid Area “Y” is always a liquid Area “Z” is always a gas On the line = both (equilibrium) Critical Point = liquid state cannot exist beyond this temperature Triple Point = all 3 states of matter in equilibrium
Phase Diagram – Y III Sublimation (Solid to gas) ◦ The process of a solid becoming a gas by SKIPPING the liquid state ◦ Requires a GAIN of energy (heating) Deposition (Gas to Solid) ◦ The process of a gas becoming a solid by SKIPPING the liquid state ◦ Requires a LOSS of energy (cooling) Note: Since the Y-diagram is a pressure/temperature comparison, ANY change can occur by simply altering the pressure.