Introduction to Matter Properties of Matter

Review: What is Matter? Matter: anything that has mass and volume Mass – the in something Volume – the something occupies Think: which of the following is matter? (Put an M beside terms that are matter): A car - Dust Time - Air You - Pain Sound - Calcium Heat -Light Water - Gravity Hydrogen - A desk Thunder -Energy Lightning - A rainbow

What is a property? When observing and describing matter, we often note properties of matter… Property: a characteristic of a that can be 2 Types: Physical and Chemical Properties

Physical Properties Physical property: a property that can be observed changing the of the substance. Often used to things Examples: color, shape, mass, melting point, point, , solubility, and specific heat.

Special Physical Properties Melting point: the temperature at which a substance changes from a to a at a given pressure water = Boiling point: the temperature at which a substance changes from a to a at a given pressure These characteristics are the for pure substances regardless of mass or volume!

Special Physical Properties Density is the amount of per unit of , D= Density can be used to identify a substance. Water’s density is

Chemical Properties Chemical property: a property that can only be observed by of the substance Examples: flammability ability to rust reactivity (like with vinegar)

THINK! Classify the following as either chemical or physical properties: (Label each with C or P) Is shiny Melts easily Has a density of 2.3 g/cm3 Tarnishes in moist air Does not react with hydrogen Reacts with water Boils at 100oC Is red Is a good conductor of heat

THINK! Compare and contrast Physical and Chemical Properties.

Changes of Matter EVERYTHING changes… how would you define ‘change’ in your own words? In science, we say change is

Knowing the difference between a physical property and a chemical property makes it easier to differentiate between a physical and chemical change…. Any guesses?

Physical Change Physical change: a change that occurs that does not change the identity of the substance ( ) Affects the physical properties of a substance Examples: Melting ice Freezing Kool-aid Tearing paper

Chemical Change Chemical change: a change that occurs causing the identity of the substance to change (the chemical structure is altered) Soured milk Effervescent tablets (Alka Seltzer) A chemical change is called a

Chemical Change Chemical Change: Changes the chemical makeup of the substance ( ) Can’t be undone or by physical changes Indicators of a chemical change: Presence of light Presence of heat Presence of a gas Color change Formation of a precipitate (formation of a solid from liquids)

THINK! Classify the following as either physical or chemical changes: (Label each P or C) Mixing sugar in lemonade Plants using CO2 and H2O to form O2 and sugar Boiling water Frying an egg Rust forming on metal Fruit rotting Separating salt and water by evaporation

THINK! What’s the difference between a property of matter and a change of matter (i.e. what is the difference between a physical property and a physical change)?