This document discusses the basic properties and classification of elements. It defines an element as a pure substance made of identical particles called atoms that cannot be broken down further. Each element has a unique set of characteristic physical and chemical properties that can be used to identify it. Elements are classified as metals, nonmetals or metalloids based on whether they are shiny conductors of heat and electricity like metals, or dull insulators like nonmetals, or exhibit some properties of both.

1. Chapter 5, Sec 1Chapter 5, Sec 1
Notes from 10/25/10Notes from 10/25/10

2. Elements, the SimplestElements, the Simplest
SubstancesSubstances
 AnAn elementelement is a pure substance that cannot beis a pure substance that cannot be
separated or broken down into simplerseparated or broken down into simpler
substances by physical or chemical means.substances by physical or chemical means.
 AA pure substancepure substance is a substance in which allis a substance in which all
of the “building-block” particles are identical.of the “building-block” particles are identical.
 For elements, the building-block particles areFor elements, the building-block particles are
calledcalled atoms.atoms.

3. Classifying ElementsClassifying Elements
 Each element can be classified by itsEach element can be classified by its
unique set of characteristic properties.unique set of characteristic properties.
 Characteristic propertiesCharacteristic properties include physicalinclude physical
properties and chemical properties.properties and chemical properties.
 Each element can be identified by itsEach element can be identified by its
unique set of properties.unique set of properties.

4. Grouping ElementsGrouping Elements
 Elements are classified as metals, nonmetals,Elements are classified as metals, nonmetals,
or metalloids based on their properties.or metalloids based on their properties.
 MetalsMetals are shiny and conduct heat and electricare shiny and conduct heat and electric
current.current. NonmetalsNonmetals are dull in appearance andare dull in appearance and
do not conduct heat or electric current.do not conduct heat or electric current.
 MetalloidsMetalloids have properties of both metals andhave properties of both metals and
nonmetals.nonmetals.