Matter & States of Matter PESS 1

Describing Matter Matter is anything that has mass and takes up space All the “stuff” around you is matter, even things you don’t see such as air is matter Properties of matter –Properties of matter is either physical or chemical

Describing Matter Physical properties of matter –A physical property is a characteristic of matter that can be observed without changing it into another substance –Examples would be: State (solid, liquid, or gas) Color Shape Texture Others?

Describing Matter Chemical properties of matter –A chemical property describes the ability of matter to change into a different substance –Examples of chemical changes: Ability to burn Ability to react to an acid Ability to rust or tarnish

Describing Matter Forms of matter: –Elements: A pure substance that cannot be broken down by physical or chemical means Elements are the simplest substance or form of matter –Compounds: A combination of two or more elements When the elements combine they form compounds that have properties different from the uncombined elements

Describing Matter Forms of matter –Mixtures: Made of two or more substances that are mixed together, but not chemically combined Each substance keeps its individual properties Mixtures can be separated by normal means Types of mixtures –Heterogeneous mixtures –Homogeneous mixtures

Describing Matter Heterogeneous Mixtures –A type of mixture in which the parts of the mixture are noticeably different from one another. –The different parts can be seen –Examples: salads, hamburgers, soil – any mixture that the different parts can be seen Homogeneous Mixtures –Mixed so well that the different parts cannot be seen

Describing Matter Solutions –When one substance dissolves into another substance a solution forms Colloids –A homogeneous mixture that does not separate over time –Generally you cannot see through them Suspensions –A heterogeneous mixture that separates over time

Changes in Matter Two types of changes in matter –Physical Changes –Chemical Changes Physical changes –When a substance undergoes a physical change it is still the same substance after the change –Examples: tearing, changing color, changing state (gas – liquid – solid)

Changes in Matter Chemical changes: –A chemical change produces a new substance with properties different from the original properties –Examples: burning, reacting to an acid, rusting or tarnishing –Law of conservation of mass: states that matter cannot be created or destroyed, it can only change form

Changes in Matter Matter and thermal energy –When matter changes form energy is either released or absorbed –Endothermic change: energy is absorbed or taken in and the result is the matter feels cool –Exothermic change: energy is lost or released and the results is the matter feels warm

States of Matter StateDefinite Volume Definite Shape Movement of Particles Solid Yes Vibrating Liquid YesNoFreely moving Gas No Fast moving

States of Matter Solids: has a definite shape and a definite volume Particles in a solid –The particles are packed very close together – this causes the solid object to hold its shape –The particles are not completely motionless, but vibrate in place

States of Matter Liquids: has a definite volume, but no definite shape –Particles in a liquid: The particles are packed close together, but are free to move around – this is what causes liquids to lose to their shapes. –Properties of liquids: Surface tension: an attraction between the particles causing the liquid to “bead up”

States of Matter Properties of liquids: –Viscosity: a liquids ability to resist flowing Examples: high viscosity, like honey does not flow easy; low viscosity, like water flow easily Gases: –Does not have a definite shape or a definite volume

Changes in State Melting: change between a solid and a liquid –Melting occurs at a specific temperature, known as the melting point –At the melting point the particles start moving so fast that they break free from their fixed positions –Example: 0°C is the melting point for water

Changes in State Freezing: changes a liquid to a solid –The particles inside the liquid begin to slow down and form a solid –Freezing point is the point when this occurs Example: water freezes at 0°C Evaporation: changes a liquid into a gas –Occurs only at the surface (not throughout the liquid)

Changes in State Evaporation continued –Boiling occurs when the liquid is changing into a gas, but throughout the entire liquid –Boiling point – the temperature at which a liquid begins to boil Example: the boiling point of water is 100°C Condensation: changes a gas into a liquid –Occurs when the particles lose thermal energy and begin to slow down forming a liquid

Changes in State Sublimation: changes a solid into a gas (skipping the liquid stage) –Example: dry ice (solid form a carbon dioxide)