Journey into the Atomic
World
The Big Idea: Periodic trends in the
properties of atoms allow for a better
understanding of the world we live in.
• Atom-
http://www.kochanowicz.com/Atoms%20Photos.htm
smallest particle
•
that
an element can be
divided & still be the
same substance
• Atomos-Greek
http://www.chem4kids.com/files/atom_intro.html
http://education.jlab.org/qa/atom_model.html
“indivisible”
word meaning
2
http://www.cartage.org.lb/en/kids/science/Chemistry/Atoms/Atomic%20Stucture.htm
The Atom’s Nucleus & Beyond
• Protons
(P)- (+) charged atomic
particle; nucleus.
Identity of element
• Neutrons
•
(n)-no charge; nucleus
Quarks-make up P & N
• e-
negatively charged; e- cloud
outside of the nucleus
http://www.phys.uu.nl/~thooft/quarks.html
3
• Element
-substance w/ atoms that
are all alike. (i.e. H, He, Fe)
• Molecule-when 2 or more elements
join together chemically (O3, H2O)
• Compound-a molecule made of atoms
from different elements (NaCl, H2O)
Atoms
Elements
Compounds
Molecules
http://www.chem4kids.com/files/matter_plasma.html : Plasma video
http://www.chem4kids.com/files/matter_states.html
States of Matter and Energy
Solid- holds shape, fixed volume
• Liquid-shape of container, fixed volume
• Gas-shape & volume of container (they fill the container)
• Plasma- at extremely high temps atoms may collide
with such force that e- are knocked free from the
nuclei.
•
Identifying the Atom
• Atomic
Number - # of P.
In a
neutral atom this is also the amount of e-
http://education.jlab.org/glossary/atomicnumber.html
7
• Mass
# - sum of P & N.
Round the atomic
mass # subtract protons to get the neutrons
• Atomic
mass - average of the masses
of the naturally occurring isotopes
Atomic mass unit
(amu)
SI unit of atomic
particles
http://imagine.gsfc.nasa.gov/docs/science/try_l1/cosmic_rays.htm
8
The Changing of the Neutron
• Isotopes - atoms that have same #
of P but different amount of N.
Unstable atom - atom whose
nucleus can change it composition
Radioactive - result of unstable
atoms
http://oceanexplorer.noaa.gov/edu/learning/15_seamounts/activities/coral.html
http://www.bcpl.net/~kdrews/introterms/intro4.html
9
Isotope Notation
http://www.dreamstime.com/royalty-free-stock-images-colorful-cartoon-car-set-image23263769
http://en.wikipedia.org/wiki/Isotope