Page 106 - Microsoft Word - LessonPlan-Overview.doc
P. 106
Unit 3: Matter Page 18
first shell is filled) will be in the It needs eight electrons to be
second shell. satisfied.
Electron Sharing Luckily, two Hydrogen atoms
happen by. Each one of them has
Electrons provide the size and only one electron in its outer shell
stability of the atom and, as such, and needs one more to be
the mass and the structure of all satisfied. If both Hydrogens share
matter. Electrons are also the key their one electron with the Oxygen,
to all electromagnetic energy. But the oxygen has eight electrons and
wait, that’s not all! It is the is satisfied. Also, if the Oxygen
number of electrons in an atom shares an electron
that determines if and how atoms with each Hydrogen,
come together to form molecules. then both Hydrogens
Electrons determine how and what are satisfied as well.
matter will be. Just like your mother
told you, it’s nice to share. It is this
Atoms like to feel satisfied and sharing of electrons that makes
they feel satisfied if they are “full”. atoms come together to form
An atom is full if it eats four hot molecules.
dogs and a large fry. (Just kidding.
) An atom is “full” if its outer In the upcoming lessons, we are
electron shell has as many going to begin taking a close look
electrons as it can hold or if there at the different forms of matter
are eight or a multiple of eight (16, that these strange and mysterious
24 etc.) electrons in the outer atoms can take. Before we do,
shell. This is called the octet rule however, it’s worth taking a bit of
and works most of the time, but is time to get a handle on the
not perfect. concept of density.
If an atom is not full, it is not What is Density?
satisfied. An unsatisfied atom
needs to do something with its Density is basically how tightly
electrons to be happy. Luckily packed atoms are.
atoms are very friendly and love to Mathematically, density is mass
share. Most atoms are not satisfied divided by volume. In other words,
as individuals. The oxygen atom it is how heavy something is,
has six electrons in its outer shell. divided by how much space it takes
up. If you think about atoms as
© 2010 Supercharged Science www.ScienceLearningSpace.com
106
