Matter and Change - Bartlett High School

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Chemistry Joke What do you call iron blowing in the wind?

Febreeze!

“Matter and Change”

Chemistry

- the study of matter and its changes • Matter

space - anything that has mass and takes up

Air and smoke are examples of matterLight and heat are energy, not matterMass

- quantity of matter (numbers of atoms or molecules)

Weight

- 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

plasma

Pure Substances

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

Mixtures

• •

2 Types

Homogeneous

• • • •

Composed of only one phase of matter Completely uniform throughout Also called a solution Ex: salt water, air

Heterogeneous

Non-uniform distribution

Ex: apple, salad Can be separated by physical means

Filtration, distillation, chromatography

Physical Separation

of a Homogeneous Mixture by Distillation

liquid alcohol and water alcohol

Physical Separation

of a Heterogeneous Mixture Using Magnetism

Physical Separation of a Homogeneous Mixture Using Chromatography

Physical Properties

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 !!

Chemical Properties of Matter

• 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:

Energy

is absorbed or released (temperature changes) 

Color

changes 

Gas

is produced (bubbling, fizzing, or odor change; smoke) 

Precipitate

is formed - a solid that separates from solution (won’t dissolve) 

Irreversibility

- 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.!

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