Chemistry Joke What do you call iron blowing in the wind?
- the study of matter and its changes • Matter
space - anything that has mass and takes up
– Air and smoke are examples of matter – Light and heat are energy, not matter • Mass
- quantity of matter (numbers of atoms or molecules)
- measure of gravitational attraction
– Dependent on gravity of location
Study of Matter
• • • • • •
States of Matter Classifications of Matter Physical Properties of Matter Physical Changes of Matter Chemical Properties of Matter Chemical Changes of Matter
States of Matter
• • • •
Gas - indefinite volume and shape Liquid - definite volume, indefinite shape Solid - definite volume and shape Plasma – a gas that has a charge because it has been heated and has lost its electrons.
Classifications of Matter
• Elements – Simplest form of matter / building blocks – Composed of only one type of atom – Cannot be simplified – Ex: Any element on periodic table • Compounds – Substances that can be separated only by chemical means into simpler substances – Can be written as a chemical formula – Ex: water, H 2 O; baking soda, NaHCO 3 ; ammonia, NH 3
• • • •
Composed of only one phase of matter Completely uniform throughout Also called a solution Ex: salt water, air
Ex: apple, salad Can be separated by physical means
Filtration, distillation, chromatography
of a Homogeneous Mixture by Distillation
liquid alcohol and water alcohol
of a Heterogeneous Mixture Using Magnetism
Physical Separation of a Homogeneous Mixture Using Chromatography
substance of Matter Properties that can be observed and measured without changing the composition of the Color Solubility Electrical Conductivity State of Matter (solid, liquid, gas) Density Melting and Boiling point Metallic Characteristics (malleability, ductility, & luster) Thermal Conductivity Magnetic Properties
Physical Changes of Matter
Changes in Form not Substance
• Phase changes are physical !!
– Melting, freezing, boiling, condensing, evaporating • Tearing, breaking, cutting, crushing • Dissolving is a physical change !!
• Ability of a substance to undergo a chemical reaction and form a new substance • Flammability / Combustibility • Acidic or basic • Reactivity
Chemical Changes of Matter Indicators that a chemical change may have happened:
is absorbed or released (temperature changes)
is produced (bubbling, fizzing, or odor change; smoke)
is formed - a solid that separates from solution (won’t dissolve)
- not easily undone
Words Associated with Chemical Change Burn Decompose Corrode Rot Rust Ferment Cook Explode -----------
Chemical Reactions of Matter Starting substances called reactants change to form products.
Reactant + Reactant → Product
The Law of Conservation of Mass (of Matter!) • •
In any physical or chemical change, mass is neither created nor destroyed; it is CONSERVED!
In other words, the mass of the reactants will ALWAYS equal the mass of the products.
43.43 g Original mass = 43.43 g Final mass reactants → product
Chemistry Joke Q: H hydrogen peroxide. What is H 2 O 4 2 O is water and H ? 2 O 2 is A: Drinking, Bathing, Etc.!