What Are ElementsChapter 12 Lesson 1Pages E6 – E11

Objectives Understand that all matter is made

up of the same basic particles Recognize atoms as fundamental

particles of matter Identify the basic parts of an atom Identify an element as any type of

matter made up of only one kind of atom

Main IdeaAll matter is made up of elements. The smallest piece of an element is called an atom.

VOCABULARY

ELEMENTA substance that cannot be broken apart into other substances.

These are the building blocks of matter.

ATOMThe smallest particle of an element that still has the properties of that element.

ELECTRONSParticle in an atom that has a negative charge.

NUCLEUSCentral core of an atom

PROTONParticle in the nucleus of an atom that has a positive charge.

NEUTRONParticle in the nucleus of an atom that has NO charge.

MOLECULETwo or more atoms joined together by chemical bonds.

Elements Page E6 All matter is made up of

elements. Some substances (like diamonds)

are made from a single element Most substances are made from 2

+ elements

Atoms Page E6 The smallest part of an element Can only be seen by special

microscopes Ancient Greek philosophers were

the first to suggest all matter is made of atoms.

1803 - DaltonSolid spheres of different

sizes and masses

1897 - ThomsonBall of positive

charged has negatively charged electrons located throughout.

1911 - RutherfordSmall, dense nucleus

surrounded by mostly empty space. Electrons move in that space.

1913 - BohrElectrons travel in

specific orbits around the nucleus.

1926 - SchrodingerElectrons clouds or orbitals

show the probability of finding an electron in a particular location.

Organization of AtomsElectrons have very little

mass. The nucleus accounts for most of the mass.

The nucleus is made up of protons and neutrons

Organization of Atoms Protons have a positive charge,

electrons have a negative charge, and neutrons have no charge.

Coal, graphite, and diamonds are all carbon, differing in the way their atoms are arranged.

Graphite Atoms are arranged in sheets the

separate easily.

Diamond The hardest natural

substance found on Earth.

Atoms packed tightly together with each atom bonded to four other atoms.

This gives diamonds their hardness

Coal Anthracite coal

contains 90 to 98 percent pure carbon

Important fossil fuel formed from dead plants

Elements Alone and Joined An elements properties come

from the atoms that compose it. Atoms can join together through

chemical bonds to form molecules

Molecules can contain atoms of the same element or atoms of different elements.

QuestionWhat are the tiny particles

that make up an atom?

AnswerElectronsProtonsNeutrons

QuestionHow do atoms, molecules,

and elements differ?

AnswerAtoms are the smallest

particles of an element. Molecules are two or more

atoms joined together. Elements are the building

blocks of all matter

QuestionWhy do the different forms of

carbon have different properties?

AnswerBecause their atoms are

arranged differently.