Chem 100 Module 1

Matter

Anything that takes up space and has mass

States of matter

solid, liquid, gas

Characteristics of a solid

• atoms or molecules packed tightly in a fixed location

• molecules vibrate in place

• solids have a fixed volume and shape

Types of solids

1. Crystalline solid

2. Amorphous solid

Crystalline solids

atoms or molecules arranged in geometric patterns with repeating order

Amorphous solid

atoms or molecules that do not have an order

Characteristics of liquids

• atoms or molecules are close together, but are free to move (slide)

• Fixed volume

• Take the shape of the container

Characteristics of gases

• atoms and molecules are seperated by large distance and free to move

• compressable

• take the shape and volume of the container

Pure Substance

matter with a uniform and defined chemical composition (has a formula). It is composed of only one type of atom or molecule

Characteristics of an element

• simplist form of matter

• cannot be broken down into simpler substances

• represented by symbols found on the periodic table

Characteristics of Compounds

• a pure substance composed of two or more elements in fixed difinite proportions

• substances that can be broken down into simpler substances by chemical means

Mixtures

physical blend of two or more substances (different atoms or molecules)

Types of mixtures

1. Homogeneous

2. Heterogeneous

Homogeneous

• uniform composition

• can be sperated through distillation

Heterogeneous

• not uniform composition

• seperated by physical means like filtration or magnets

Physical Property

• quality that is observed without changing the substance composition

Examples of Physical Properties

• odor

• density

• hardness

• solubility

• melting point

• boiling point

• color

Chemica Property

ability of a substance to form a new substance through chemical reaction

Physical Change

A change that alters the material without changing composition (rearranging molecules, does not break bonds); Change apperance not composition.

Examples of a physical change

• bend

• melt

• boil

• split

Chemical Change

A change which results in a change in chemical composition (breaking of chemical bonds)