CHAPTER 1-INTRODUCTION TO

MATTER

MATTER• The “stuff” that makes up everything in

the universe.

• It has a variety of properties (characteristics)

• These characteristics can be used to identify substances.

• Each specific substance has its own combination of properties that can be used to identify it.

• Chemistry is the study of matter and how matter changes

Elements• The building blocks of matter, all matter

is composed of elements

• Elements are made of atoms.

• Atoms are the building blocks of elements.

How many elements do you already know?

• Elements are represented by symbols

• One or two letters, first letter ALWAYS capitalized

• Oxygen-O Aluminum- Al

• Hydrogen-H Gold-Au

• Mercury-Hg Sodium-Na

COMPOUNDS• Elements can exist uncombined or combined.• A compound is a substance made of two or

more elements in a specific ratio• Compounds are represented by formulas • A formula shows the ratio of elements in the

compound• Ex. H2O, CO2, NaCl

Element or Compound?

• Mixtures are made of two or more substances-elements, compounds, or both, that are together in the same place but are not chemically combined.

• Ex. Salt water, air, soup, salad

Compound vs. mixture?

• Substances in mixtures keep their individual properties. Ex. Chex mix

• Substances in compounds change their individual properties Ex. NaCl (salt)

Changes in Matter

• Physical changes alter the physical appearance but do not turn material into a new substance

• Changes in :

• Ex. Water melting, freezing, evaporating

• The water looks different, but it is still H2O

Chemical Changes

• Chemical changes or chemical reactions, change matter into new substances

• The change is permanent

• Ex. Burning paper, baking a cake, metal rusting

Chemical or Physical?

• Matter can change in one of two ways, physically or chemically

Ch. 1-2 Measuring Matter

• What is the difference between weight and mass?

Volume• The amount of space an object

occupies.

• To measure a rectangular object:V= Length x Width x Height

• To measure a liquid, use a graduated cylinder

• To measure and irregularly shaped object, use the displacement method

Density• The measure of how much mass is

contained in a given volume

• A small block of wood floats on water. It has a volume of 2 cubic centimeters and a mass of 20 grams. What is the density?

Chapter 1-3 Particles of Matter

Early ideas about atoms• Democritus-Greek

philosopher, lived about 440 B.C.

• He called the smallest piece of a substance “atomos”, Greek for “uncuttable”

John Dalton-1802

• Proposed atomic theory

• Imagined atoms to be like tiny marbles that are impossible to break

• In any element, all the atoms are exactly alike

• Atoms of different elements are different

• Atoms of two or more elements can combine to form compounds

• Atoms of each element have a unique mass

• The masses of the elements in a compound are always in a constant ratio

Ideas about atoms today

• There are 2,000 billion billion atoms of oxygen in one drop of water

• Atoms are linked by chemical bonds

• A combination of two or more atoms that are bonded together is a molecule