Transcript Atoms Vs. Molecules

Atoms and Molecules
The power of tiny things
Structure of an Atom
Three Kinds of Particles:
Protons (+) Inside nucleus
Neutrons Inside nucleus
Electrons (-) Moving rapidly around the nucleus
The Role of Electrons
Moving so quickly that it is impossible to pinpoint an
electrons location at any given time.
Think of the blades of a fan.
Electrons move around the nucleus much
like the fan blades, but in 3 dimensions.
Just the facts:
Just how small is an atom?
A penny contains about
20,000,000,000,000,000,000,000 atoms.
When an atom gains or loses electrons, it is called
an ion. Ions can form when two atoms chemically
bond to form a new substance.
Na+ (sodium) + Cl- (chlorine) = NaCl (salt)
More facts:
Isotopes
Isotopes (atoms with different numbers of
protons and neutrons) can become unstable
and are called radioactive. They can be used
to identify certain chemical reactions, or for
nuclear development.
Atomic Forces:
Gravitational force
Electromagnetic force
Atomic Forces:
Strong force (in the nucleus)
Hold the
nucleus together
Weak force (in neutrons)
A neutron can change into
a proton or electron
little particles, BIG SPACES.
Most of an atoms mass comes from the
protons and neutrons in the nucleus.
An atom’s volume is mostly due to the
electron cloud around it.
Did you know?
A human hair is about one MILLION atoms thick!!!!
Molecules
Molecules are two or more
atoms joined together in a
set ratio.
The atoms are joined by
the outer ring of electrons,
called the valence
electrons.
Putting it all in perspective
http://education.jlab.org/atomtour/listofparticles.html
http://www.classzone.com/books/earth_science/terc/content/investigations/es0501/es0501page06.cfm
http://www.youtube.com/watch?v=MUeFzvHz8Bw