Chemistry – The Study of Matter

Alchemists hard at work.

Chemistry The study of the composition,

structure, and properties of matter and the changes it undergoes.

Branches: Organic Inorganic Physical Analytical Biochemistry Theoretical

Research

Basic Reasearch Increasing knowledge

Applied Research Solve a specific problem

Technological Development Production and use of products to

improve quality of life

Matter 4 states of matter

Solids Liquids Gases Plasma

Kinetic Molecular Theory (KMT) Particles are in constant motion The kinetic energy of the particles

increases as temperature increases

Solids

Very low KE – particles vibrate

Fixed shape Fixed volume

Liquids

Low KE – particles can move around but are close together

Variable shape Fixed volume

Gases

High KE – particles separate and move freely

Variable shape Variable

volume

Plasma

Very high KE particles collide with enough

energy to break into charged particles

Gas-like – variable shape and volume

Ex: stars, fluorescent light bulbs

Phases of Matter

Matter Flowchart

Homogeneous Mixture

(solution)

Is the composition uniform?

noyes

MATTER

Can it be physically separated?

Heterogeneous Mixture Compound Element

MIXTURE PURE SUBSTANCE

yes no

Can it be chemically decomposed?

noyes

Colloids Suspensions

Classification of Matter

Examples: Graphite element Pepper heterogeneous mixture Sugar (sucrose) compound Paint heterogeneous mixture Soda solution (homogeneous

mixture)

Pure Substances

1. Element Composed of identical atoms Ex: Copper wire, aluminum foil

Pure Substances

2. Compounds Composed of

two or more elements in a fixed ratio

C

H

OH

C C

C

C CH

HH

H

H

HOH

O

OH

HOOH

Properties differ from individual elementsEx: glucose, caffeine

Mixtures

Combination of 2 or more pure substances

1. Homogeneous mixtures – AKA solutions

2. Colloids3. Suspensions

Heterogeneous mixtures

Colloids scatter light, making a beam visible. Solutions do not

scatter light.

solutioncolloid

Which glass contains a colloid?

Mixtures

1. Solution Homogeneous Very small particles No Tyndall effect Particles don’t settle Ex: rubbing alcohol

Mixtures

2. Colloid Heterogeneous Medium sized

particles Tyndall effect Particles don’t

settle Ex: milk

Examples Dispersing Medium

Dispersed Substance

Colloid Type

Fog, aerosol sprays Gas Liquid Aerosol

Smoke, airborne bacteria

Gas Solid Aerosol

Whipped cream, soap suds

Liquid Gas Foam

Milk, mayonnaise Liquid Liquid Emulsion

Paint, clays, gelatin Liquid Solid Sol

Marshmallow, Styrofoam

Solid Gas Solid foam

Butter, cheese Solid Liquid Solid emulsion

Mixtures

3. Suspension Heterogeneous Large particles Tyndall effect Particles settle Ex: fresh squeezed

lemonade

Mixtures – Colloid, suspension, or solution??

Examples Mayonnaise colloid Muddy water suspension Fog colloid Salt water solution Italian salad dressing suspension

The Periodic Table

Rows – Periods Columns – Groups or Families Three main types of elements

1. Metals2. Nonmetals3. Metalloids

Metals

Conducts heat and electricity Malleable Ductile

Nonmetals

Many are gases at room temperature

Solids are brittle

Metalloids

Touch the stair-step line (except Al)

Some characteristics of metals and nonmetals

Semiconductors