Chemistry

Chapter 3

Notes #2

Matter

Pure Substances(can be represented

by a chemical Formula)

Mixtures(can be separated By physical means)

Elements Compounds Homogenous Heterogeneous

Solution Suspension

Colloid

Matter- Pure Substances All samples of matter are composed of atoms…

The smallest particles possessing the properties of an element Fundamental chemical substances from which all other

substances are made

When 2 or more types of atoms combine and cannot be separated by physical means = compound! (must be separated by chemical change)

Mixtures To tell them all apart:

Colloid and solution V. Suspension A suspension settles out, making it different from

both of the other two.

Colloid V. solution The TYNDALL EFFECT : Shine a beam of light

through each. If you can see the light beam traveling thru = colloid (the light bounces off the particles that are suspended). No light beam = solution

Solution Suspension Colloid

Appearance Clear, transparent and homogeneous

Cloudy, heterogeneous, at least two substances visible

Cloudy but fairly uniform

Particle Size smallest biggest Medium (intermediate)

Effect of Light Tyndall Effect

none -- light passes through, particles do not reflect light

variable light is dispersed by colloidal particles

Effect of Sedimentation

none particles will eventually settle out

none

Separating Mixtures Mixtures can be separated by physical means

Filtration – porous barrier to separate Chromatography- separates parts of a mixture

on the tendency of each part to be drawn across the surface of another material

Distillation – differences in boiling points Crystallization – results in the formation of

solid particles Change of state