Properties of Properties of MatterMatter

SNC 1DSNC 1D

ProblemProblem Question: What Question: What

physical and physical and chemical properties chemical properties should braces (used should braces (used to straighten teeth) to straighten teeth) possess in order to possess in order to attain its desired attain its desired goal (to straighten goal (to straighten the teeth) while not the teeth) while not presenting a health presenting a health hazard to the hazard to the individual?individual?

HypothesisHypothesis

Discuss with a few neighbours the Discuss with a few neighbours the question that has been presented to question that has been presented to you and brainstorm the desired you and brainstorm the desired physical and chemical properties physical and chemical properties that it should possess. (5 minutes)that it should possess. (5 minutes)

GO!!!GO!!!

Physical PropertiesPhysical Properties

A physical property is a A physical property is a characteristic or description of a characteristic or description of a substance that may help to identify substance that may help to identify it.it.

A key concept is that when a A key concept is that when a substance undergoes a physical substance undergoes a physical change, only the substance’s change, only the substance’s appearance has changed. appearance has changed.

Using your sensesUsing your senses

Although this is not recommended in Although this is not recommended in a science lab, you’ve been a science lab, you’ve been describing physical properties using describing physical properties using your senses:your senses: SightSight Touch:Touch: Taste:Taste: Smell:Smell:

Describing PropertiesDescribing Properties

PropertyProperty Describing the PropertyDescribing the Property

ColourColour Black, white, red …Black, white, red …

TextureTexture Fine, coarse, smooth, gritty …Fine, coarse, smooth, gritty …

OdourOdour Odourless, spicy, salty, burnt …Odourless, spicy, salty, burnt …

LustreLustre Shiny, dull …Shiny, dull …

ClarityClarity Clear, cloudy, opaque …Clear, cloudy, opaque …

TasteTaste Sweet, sour, salty, bitter, Sweet, sour, salty, bitter, tasteless …tasteless …

The States of MatterThe States of Matter

One way of describing a physical One way of describing a physical property is to observe its state while property is to observe its state while at room Temperature (22°C): solid, at room Temperature (22°C): solid, liquid or gas.liquid or gas.

From this property, we can deduce From this property, we can deduce two other properties qualitatively two other properties qualitatively (without numerical values): relative (without numerical values): relative shape and volume. shape and volume.

SolidsSolids

When a substance is in its solid When a substance is in its solid state, it has a definite or fixed state, it has a definite or fixed (unchanging) shape. Its volume is (unchanging) shape. Its volume is also fixed. also fixed.

THINK: An ice cube is placed in a THINK: An ice cube is placed in a glass. The ice cube does not take glass. The ice cube does not take the shape of the glass because its the shape of the glass because its shape is not changing, hence, its shape is not changing, hence, its volume remains the same.volume remains the same.

LiquidsLiquids

When a substance is in its liquid state, When a substance is in its liquid state, it has an indefinite or changing shape, it has an indefinite or changing shape, but its volume is fixed. but its volume is fixed.

THINK: Water is poured into a glass. THINK: Water is poured into a glass. The water takes the shape of the glass, The water takes the shape of the glass, but it will only occupy the space which but it will only occupy the space which is dictated by its volume. This is why is dictated by its volume. This is why the glass can be half full or half empty.the glass can be half full or half empty.

GasesGases

When a substance is in its gaseous When a substance is in its gaseous state, it has an indefinite or changing state, it has an indefinite or changing shape and an indefinite volume. shape and an indefinite volume.

THINK: In a room, is there a place in THINK: In a room, is there a place in the room where there is no air? No the room where there is no air? No because regardless of how much air because regardless of how much air is in the room, the air will occupy the is in the room, the air will occupy the entire room; regardless of the shape entire room; regardless of the shape of the room. of the room.

State – Shape - VolumeState – Shape - Volume

StateState SolidSolid LiquidLiquid GasGas

ShapeShape DefiniteDefinite IndefiniteIndefinite IndefinitIndefinitee

VolumVolumee

DefiniteDefinite DefiniteDefinite IndefinitIndefinitee

HardnessHardness

Hardness is a measure of the Hardness is a measure of the resistance of a solid to being resistance of a solid to being scratched or dented. Diamonds tend scratched or dented. Diamonds tend to be the used excessively for cutting to be the used excessively for cutting other objects due to its superior other objects due to its superior hardness. hardness.

MalleabilityMalleability

Malleability is an object’s ability to be Malleability is an object’s ability to be shaped into different forms (i.e. shaped into different forms (i.e. flattened, bent, etc.). Metals tend to be flattened, bent, etc.). Metals tend to be malleable. For example, aluminum is malleable. For example, aluminum is used at home in the form of wrapping used at home in the form of wrapping because it can be flattened into thin because it can be flattened into thin sheets and it can be shaped into just sheets and it can be shaped into just about any solid object. Substances, like about any solid object. Substances, like sulfur, which are not malleable are said sulfur, which are not malleable are said to be brittle, because they shatter. to be brittle, because they shatter.

DuctilityDuctility

Ductile objects have the ability of Ductile objects have the ability of being pulled into long wires when in being pulled into long wires when in solid form. Copper is ductile solid form. Copper is ductile because it can be made into very because it can be made into very long copper wires.long copper wires.

Melting and BoilingMelting and Boiling

Substances are bound by Temperature Substances are bound by Temperature limits in which their shape and volume alter limits in which their shape and volume alter as a result of their state. We refer to a as a result of their state. We refer to a melting point when a substance transforms melting point when a substance transforms itself from a solid to a liquid (or vice versa). itself from a solid to a liquid (or vice versa). We refer to a boiling point when a We refer to a boiling point when a substance transforms itself from a liquid substance transforms itself from a liquid into a gas (or vice versa). An ice cube into a gas (or vice versa). An ice cube melts to become liquid water at 0°C and melts to become liquid water at 0°C and then become a gas at 100°C (and vice then become a gas at 100°C (and vice versa).versa).

CrystallizationCrystallization

Crystallization is a substance’s Crystallization is a substance’s ability to form into a crystal when in ability to form into a crystal when in solid form. They normally form solid form. They normally form regular patterns (sometimes cubes) regular patterns (sometimes cubes) for example quartz, various salts, for example quartz, various salts, etc.etc.

SolubilitySolubility

Solubility is a substance’s ability to Solubility is a substance’s ability to dissolve in a solvent (water). When dissolve in a solvent (water). When drinking tea or coffee, some people add drinking tea or coffee, some people add sugar, which dissolves into the solvent. sugar, which dissolves into the solvent. An additional property associated with An additional property associated with solubility is a substance’s saturation solubility is a substance’s saturation level. If you can add sugar to the coffee level. If you can add sugar to the coffee and it dissolves, we say that the coffee is and it dissolves, we say that the coffee is unsaturated (meaning that it can unsaturated (meaning that it can dissolve more sugar). dissolve more sugar).

SolubilitySolubility

The point at which you can no longer The point at which you can no longer add any more sugar, such that it add any more sugar, such that it dissolves is its saturation point. If dissolves is its saturation point. If you can add sugar to the coffee and you can add sugar to the coffee and it no longer dissolves, we say that it no longer dissolves, we say that the coffee is supersaturated.the coffee is supersaturated.

ViscosityViscosity

Viscosity is an substance’s ability to Viscosity is an substance’s ability to flow when in its liquid form. Thick flow when in its liquid form. Thick liquids are said to be viscous such as liquids are said to be viscous such as honey or maple syrup. Water would honey or maple syrup. Water would have a relatively low viscosity level.have a relatively low viscosity level.

DensityDensity Density is a measure of matter per unit of Density is a measure of matter per unit of

space occupied expressed in g/L, kg/L, space occupied expressed in g/L, kg/L, mg/mL, etc.mg/mL, etc.

DENSITY = DENSITY = MASS . MASS .VOLUMEVOLUME

THINK: A standard box is filled with THINK: A standard box is filled with pillows, while another standard box is pillows, while another standard box is filled with books. They occupy the same filled with books. They occupy the same space, but have completely different space, but have completely different masses. Hence the box of books have a masses. Hence the box of books have a higher density.higher density.

DensityDensity

Example: A substance has a mass of Example: A substance has a mass of 380.0g and occupies 75mL. What is 380.0g and occupies 75mL. What is its density?its density?

DensityDensity

Example: A substance has a mass of Example: A substance has a mass of 380.0g and occupies 75mL. What is 380.0g and occupies 75mL. What is its density?its density?

DENSITY = DENSITY = MASS . MASS .

VOLUMEVOLUME Density = Density = 380.0 g380.0 g

75mL75mL Density ≈ 5.1g/mL Density ≈ 5.1g/mL

In summaryIn summary

When water undergoes a physical When water undergoes a physical change, we can still say that it is change, we can still say that it is water. It can be:water. It can be: warm water (heated)warm water (heated) solid water (frozen)solid water (frozen) salty water (salt dissolved into water)salty water (salt dissolved into water) crystallized water (water in the form of crystallized water (water in the form of

a snowflake)a snowflake)

Chemical PropertiesChemical Properties

A chemical property describes the A chemical property describes the behaviour when a substance is behaviour when a substance is introduced (or reacts) with another introduced (or reacts) with another substance. When a chemical substance. When a chemical reaction has occurred, a new reaction has occurred, a new substance is produced with new substance is produced with new physical properties. physical properties.

CombustibilityCombustibility

Combustibility is a property that Combustibility is a property that describes the ability of a substance describes the ability of a substance to react with oxygen to produce to react with oxygen to produce carbon dioxide (COcarbon dioxide (CO22). A substance is ). A substance is combustible or flammable if it burns combustible or flammable if it burns when introduced to a flame. If a when introduced to a flame. If a substance does not burn when substance does not burn when introduced to a flame, then it is said introduced to a flame, then it is said to be nonflammable. to be nonflammable.

Reaction to AcidsReaction to Acids

Scientists conduct acid tests to Scientists conduct acid tests to determine whether a substance will determine whether a substance will react to acid. By placing a drop of react to acid. By placing a drop of acid on the substance, the substance acid on the substance, the substance will either react by releasing will either react by releasing bubbles of gas or not react at all.bubbles of gas or not react at all.

AlloysAlloys

Later in the course, we will discuss Later in the course, we will discuss the classification of elements in the classification of elements in terms of their properties within the terms of their properties within the context of the Periodic Table of context of the Periodic Table of Elements. Elements.

One such classification of elements One such classification of elements is to divide them between those that is to divide them between those that are metals and those that are non-are metals and those that are non-metals. metals.

AlloysAlloys

We will see that non-metals react We will see that non-metals react with other non-metals and metals, with other non-metals and metals, but metals do NOT react with other but metals do NOT react with other metals. The key word here is “they metals. The key word here is “they will not REACT” together, but metals will not REACT” together, but metals can be boiled into liquid form, mixed can be boiled into liquid form, mixed together and then allowed to cool. together and then allowed to cool. The cooled substance will form an The cooled substance will form an alloy: a mixture of metals. alloy: a mixture of metals.

AlloysAlloys

Common alloys include:Common alloys include: SteelSteel Gold alloy (jewelry form) – not pure Gold alloy (jewelry form) – not pure

goldgold Nickel alloyNickel alloy Titanium alloyTitanium alloy BronzeBronze

Common AlloysCommon Alloys

MetalMetal StiffnesStiffnesss

SpringinSpringinessess

Ability Ability to bendto bend

Ability Ability to jointo join

StainleStainless ss steelsteel

HighHigh GoodGood FairFair FairFair

Gold Gold alloyalloy

MediumMedium FairFair FairFair EasyEasy

TitaniTitanium um alloyalloy

lowlow excellentexcellent poorpoor DifficultDifficult

BracesBraces

Question: What physical and Question: What physical and chemical properties should braces chemical properties should braces (used to straighten teeth) possess in (used to straighten teeth) possess in order to attain its desired goal (to order to attain its desired goal (to straighten the teeth) while not straighten the teeth) while not presenting a health hazard to the presenting a health hazard to the individual?individual?