Physical vs. Chemical Properties The Study of Matter

What is Matter? Anything that has mass and volume Mass  the amount of matter in something Volume  the amount of space something takes up Matter Not Matter Ice cream Seawater Air Other examples? Energy Light Heat Other examples?

What is a Property? A characteristic of a substance that can be observed Physical Property Chemical Property Can be observed without changing the identity of the substance Examples Luster Melting and Boiling points Malleability Ductility Phase of matter (solid, liquid, gas) Density Solubility Odor Can ONLY be observed by changing the identity of the substance Examples Flammability Combustibility Toxicity pH Reactivity with water, air, acids, etc. Ability to rust

Why are Properties Important? Knowing the properties of a substance allows you to Identify unknown and/or related substances Make predictions about how one substance will react with another Identifying Properties Non Identifying Properties Can ID a substance because the property is unique to that substance Examples Melting & boiling point Density Solubility Conductivity Magnetism All chemical properties Cannot ID a substance because the property belongs to several substances Examples Odor (smell) Color Phase of Matter Volume Mass Note: You can combine characteristics of several these properties to identify a substance

Identifying Physical Properties Melting point  the temperature when a solid changes to a liquid Examples: Water  0C or 32F Hydrogen  -259C Boiling point  the temperature when a liquid changes to a gas Examples Water  100C or 212F Hydrogen  -252C

Identifying Physical Properties Malleability  the ability to be hammered into a thin sheet Examples: Gold Silver Aluminum Ductility the ability to be stretched into a thin wire Examples: Gold Copper Aluminum iron

Identifying Physical Properties Density the amount of mass per unit volume In simple English  how compact a material is Common Densities Liquid water  1.0 g/mL Ice  0.92 g/mL Gasoline  0.70 g/mL Gold  19.3 g/mL Hydrogen  0.00009 g/mL Mercury  13.6 g/mL (add this to your notes) How to Calculate Density D = m ÷ v D= density (units are g/mL) m = mass (in g) v = volume (in mL)

Identifying Physical Properties Solubility  the ability of one substance to dissolve in another 3 related terms Solution  mixture formed by a solute and a solvent Solute  the substance being dissolved Solvent  the substance doing the dissolving

Identifying Physical Properties Solution Solute Solvent Kool-aid Sweet tea Seawater

Identifying Physical Properties Magnetism  a force coming from one object that attracts or repels another object Examples of magnetic materials: Iron Nickle Lodestone (mineral) Conductivity  how well a material conducts heat or electricity Materials with high conductivity: Iron Water Copper Materials with low conductivity: Sulfur Oxygen Plastics

Identifying Chemical Properties Combustibility  how easily a substance catches fire pH  measure of how acidic or basic a substance is

Identifying Chemical Properties Reactivity  how well one substance reacts with another Important reactions to know Air Water Acid Base

Identifying Chemical Properties Ability to Rust  when a substance, usually iron (a metal), reacts with oxygen to produce rust. The iron and oxygen in the air react with water to form iron oxide.