Chapter 3 Properties of Matter

Section 1: What is matter?

Vocabulary Matter Volume Meniscus Mass Weight

Vocabulary Matter – Anything that has mass and takes up space Volume – Amount of space an object takes up Meniscus – Curve at a liquid’s surface

Vocabulary Mass – Amount of matter in an object Weight – Measure of the gravitational force on an object

Matter and Volume All matter takes up space (volume) No two objects can occupy the same space at the same time

Matter and Volume Liter (L) is the SI unit for volume Small liquids are measured in milliliters (mL) – 1 L = 1,000 mL All liquid is measure in L or mL

Matter and Volume Measuring liquid – Use a graduated cylinder – Accuracy matters!

Matter and Volume Read volume at the meniscus Get Eye Level

Matter and Volume Solid objects measured in cubic units – Cubic = having 3 dimensions Cubic meters -- m³ Cubic centimeters -- cm³ Volume = (length) (width) (height)

Matter and Volume Irregular shaped objects – Use water displacement to find volume

Matter and Volume Water displacement 1.Measure starting water amount 2.Place object inside graduated cylinder 3.Re-measure water amount 4.Take difference

Matter and Volume Solid objects ALWAYS measured in cubic units – cm³ Water displacement measures mL Remember….. – 1 mL = 1 cm³ So…. Convert mL reading to cm³

Matter and Mass Mass never changes based on location – Only if amount of matter changes Ex: You lose weight Ex: you cut a piece of wood in ½ Weight is amount of gravitational force – Changes based upon object’s location in the universe

Matter and Mass Mass measured in grams (g) or kilograms (kg) – 1 kg = 1,000 grams Weight measured in newton (N)

 Weight measured by spring scale Mass measured by balance scale Matter and Mass

Section 2: Physical Properties

Vocabulary Physical property Density Physical change

Vocabulary Physical property – Characteristic of a substance that does not involve a chemical change Density – Amount of matter in a given volume Physical change – A change of matter from one form to another form without a change in chemical properties

Identifying Physical Properties Physical properties can be observed or measured without changing its identity – Looking at ball’s color – Measuring the ball’s volume

Identifying Physical Properties Examples… – Color – Size – Texture / feel – Magnetism – Flexibility – Smell

Identifying Physical Properties More examples – Ductility Ability to be pulled into wires – metal – Malleability Ability to be pounded into shapes – Metal – think aluminum into various shapes/containers

State – Solid, liquid, gas Solubility – Ability to dissolve Thermal conductivity – Rate which a substances transfers heat Identifying Physical Properties

Density – Must have a unit of measurement! g / cm³ -- for solids g / mL -- for liquids – Density is constant If you double the volume of an object, then it’s mass always doubled

Identifying Physical Properties

Density and Floating / Sinking – Water density = 1 g / mL – If object density greater than 1 g / mL, then it will sink – If object density less than 1 g / mL, then it will float

Identifying Physical Properties

Physical Change: NO NEW Substance A change that affects a physical property is a physical change – Twisting a paper clip – Sanding a piece of wood

Physical Change: No new substance Most physical changes are reversible Classic example – Water  ice – Ice  water – Water  steam – Steam  water Physical changes do not change the identity of the substance

Section 3: Chemical Properties

Vocabulary Chemical property – Describes a substance’s ability to participate in chemical reactions Chemical change – Occurs when one or more substances change into an entirely new substance

Identifying Chemical Properties Chemical properties describe matters ability to change into a NEW substance Examples: – Reactivity Ability to change into a new substance – Flammability Ability to burn

Identifying Chemical Properties Physical or chemical property? – physical = something to be observed Touch, feel, look, weight, smell, etc – Chemical = composition of matter Harder to see

Identifying Chemical Properties Physical or Chemical?

Identifying Chemical Properties Physical or Chemical?

Chemical Changes & New Substance Chemical change is the process Chemical properties describe what chemical changes will take place

Chemical Changes & New Substance Signs of a chemical change – Change of color – Change of odor – Fizz or foam – Light being given off

Chemical Changes & New Substance Chemical changes almost always involve heat – Losing heat – exothermic – Gaining heat -- endothermic

Physical vs Chemical Changes Physical changes do not changes the substances composition – Ice  water  steam It’s all H₂O Chemical changes do change the composition because it’s a new substance

Physical vs Chemical Changes Most physical changes are easily undone Chemical changes are almost impossible to reverse – Think a firework explosion