Properties of Matter

There are many properties in the objects around us. Some look or feel a certain way. Others react differently under certain conditions.

Matter

Matter is all around us and it can be made up in different ways.

Composition	Definition	Visual Example
Substance	Pure forms of matter Homogeneous (same throughout) Have even or uniform composition Any element or compound
Element	Only one type of atom Ex: iron bar Found on the periodic table Cannot be broken down by chemical or physical means **Some elements exist as diatomic molecules: BrINClHOF: Br₂, I₂, N₂, Cl₂, H₂, O₂, F₂ Allotropes: different forms of an element giving different structures and properties Carbon → graphite, diamond, fullerene Oxygen → oxygen gas, ozone
Compound	Two or more types of atoms bonded together atoms have different atomic numbers Ex: brass bar (made of copper and zinc), water (H₂O) Can be broken down by chemical means 2H₂O → 2H₂ + O₂ Compounds exist in fixed ratios Ex: every water atom has 2 H to 1 O Compounds are homogeneous (same throughout)
Mixture	Physical combinations of different substances Ex: pennies, nickels, quarters, dimes Ex: sand and water Can be separated by physical means Ex: Sieving, filtering, etc.

Particle Diagrams

	A. Compound B. Mixture (2 diatomic elements) C. Monatomic Element D. Diatomic Element
	X. Element Y. Compound Z. Compound W. Mixture (1 element, 2 compounds)

Physical Properties

A physical property relates to the physical characteristics of an object. Think: how it looks or feels

Physical Property	Definition	Examples
Melting Point	temperature at which a substance melts (or freezes) determined by intermolecular forces (stronger force → higher temp) adding a nonvolatile substance decreases the melting point
Boiling Point	temperature at which a substance boils (or condenses) determined by intermolecular forces (stronger force → higher temp) adding a nonvolatile substance increases the boiling point
Flexibility	Ability of a material to bend and hold its shape	drinking straw: flexible brick: not flexible
Elasticity	Ability of a material to stretch and return to its original shape	rubber band: high elasticity brick: no elasticity
Density	A measure of how tightly packed molecules are in an object d = ^m/_V	air: low density brick: high density
Phase or state of matter	Solid, liquid, gas	water: liquid ice: solid phase steam: gas phase brick: solid phase
Texture	Relative smoothness of an object	velvet: soft texture brick: coarse
Color	Depends on reflected light	white shirt: all colors reflect off, making white brick: red light is reflected off its surface
Hardness	Resistance to scratching	diamond: highest natural hardness; can only be scratch by another diamond naturally brick: low hardness; easy to scratch
Solubility	Ability of a material to dissolve in another substance at a given temperature and pressure
Transparency	How well light passes through an object
Transparency Levels	Opaque: an object that light cannot pass through Translucent: an object that light can pass through partially (cloudy) Transparent: an object that light can pass through completely (clear)	brick: opaque stained-glass window: translucent plastic wrap: transparent
Metallic Character	whether something is a metal, nonmetal, or semimetal (metalloid) determines various properties, like conductivity, malleability, etc.	iron: metal oxygen: nonmetal
Metallic Property: Conductivity	ability of material to draw electricity through it lower electronegativity = higher conductivity	copper: good conductor rubber: nonconductor
Metallic Property: Luster	A measure of how well light reflects off an object (how shiny it is)	mirror: high luster brick: low luster
Metallic Property: Malleability	Ability to hammer (mallet) a material into sheets	aluminum: highly malleable (aluminum foil) brick: no malleability (crumbles)
Metallic Property: Ductility	Ability to pull a material into wires	copper: high ductility brick: not ductile
Metallic Property: Magnetism	The force of attraction or repulsion of magnetic materials; occurs strongly with iron (Fe), cobalt (Co), nickel (Ni)	metal paperclip: magnetic brick: not magnetic

Chemical Properties

A chemical property relates to how objects react to other objects. Think: what an object does or how it reacts

Chemical Property	Definition	Example
Flammability	Ability of a material to burn	Burning wood
Reactivity	Ability of a material to react under certain conditions	Rusting of iron
Toxicity	Ability of a material to be poisonous	Arsenic
Corrosiveness	Ability of a material to eat through other materials	Acid
Oxidation State	Ability of a material to carry a charge while bonding	Na forming a +1 charge while bonding by giving away an electron

Changes in Properties

Properties can be alter, sometimes through force (like smashing something) or through application of energy (like heating something up). The type of change that takes place is determined by whether the chemical structure remains intact.

Type of Change	Physical Change	Chemical Change
Definition	Change from one physical characteristic to another. The molecule structure does NOT change	Change one chemical characteristic to another. The molecule structure DOES change. You get new stuff.
Examples	Change in shape or phase of matter, such as water boiling or freezing H₂O (water) → H₂O (ice) : it's still H₂O Sanding a rough piece of wood to make it smooth Breaking a glass window	Burning a piece of wood A piece of metal turning to rust Carrying out a chemical reaction H₂ + O₂ → H₂O