Chapter 1

The Nature of Chemistry, Matter, and Measurement

Chemistry The science that seeks to understand

what matter does by studying

what atoms and molecules do.

Chemistry The Study of Matter

and the Changes That Matter Undergoes

Matter

Anything That Has Mass and Occupies Space

Pure Substances Elements - The Simplest Form of Matter

Basic Building Blocks of Matter

Compounds- Formed from Chemical Combination of Elements

Mixtures Homogeneous Mixture - Identical Composition Throughout

Heterogeneous Mixture - Composition Not Identical Throughout

Classification of Matter

carbon dioxide molecule

water molecule

Example: NaCl

Elements

Classification of Matter

Uniform composition throughout

Classification of Matter

Atomic Element Molecular Compound

Molecular Compound Molecular Compound

HomogeneousMixture Heterogeneous

Mixture

HomogeneousMixture

Changes of Matter

Physical Changes Chemical Changes

Chapter 1

The Nature of Chemistry, Matter, and Measurement

Solid Liquid Gas

States of Matter

Solid State Gaseous

State

Liquid State

States of Matter

Changes of Matter

Physical Changes

Produce the Same Substance in a Different State

Solid <-------------------> Liquid <------------------> Gas

Melting, Freezing, Vaporization, Condensation, Sublimation, Deposition

Physical Properties

Characterize the Physical State and Behavior of a Substance Melting point, boiling point, color, odor, taste

melting

freezing

vaporization

condensation

subl

imat

ion

depo

siti

on

Sublimation

Sublimation

Boiling

Separating Mixtures through Physical Changes “Distillation”

Separating Mixtures through Physical Changes

“Filtration”

Changes of Matter

Chemical Transformations

New Substances Formed from Starting Substances

Reactants <--------------------> Products

Chemical Properties

Observed When a Pure Substance is Transformed into Other Pure Substances

2 Na + Cl2 → 2 NaCl10.0 g Na + 15.4 g Cl2 → 25.4 g NaCl

conservation of mass

Physical vs Chemical Changes

Physical change: Solid water becomes liquid water. The composition does not change and the particles are the same.

Physical vs Chemical Changes

Chemical change: Electric current decomposes water into different substance (hydrogen and oxygen). The composition

changes and the particles are different.

Vaporization: a physical change

Push the button on a lighter without turning the flint.

The liquid butane vaporizes to gaseous butane.

The liquid butane and the gaseous butane are both

composed of butane molecules.

This is a physical change.

 Burning: a chemical change

Push the button and turn the flint to create a spark.

Produce a flame.

The butane molecules react with oxygen molecules in air to form new molecules, carbon dioxide

and water.

This is a chemical change.

Pure substance When heated and cooledWhen subjected to electric

current

Mercuric oxide(a red solid)

Produces a black solid and a colorless gas

Produces a black solid and a colorless gas

Sodium Chloride(a white solid)

Melts and solidifies to the same solid

Produces a shiny metallic substance and a green gas

Iodine(a purple solid)

Sublimes and crystallizes to the same solid

No change

Water(a colorless liquid)

Evaporates and condenses to the same liquid

Decomposes to two gases in a 1:2 ratio

Mercury(a shiny liquid)

Evaporates and condenses to the same liquid No change

Helium(a colorless gas)

No change No change

Effects of “Experiments” on Pure Substances