THE ATOM
What is an Atom?
 The smallest particle of any material.
 Each element is made up of a specific type of atom.
 EX: Hydrogen, and Oxygen
“Protons, Electrons & Neutrons
Oh My”
 The atom is made up of
three basic particles
 The Proton
 The Electron
 The Neutron
 Each particle has a specific
charge and location with in an
atom.
The Always Positive Proton
 Protons are positively
charged subatomic
particles.
 They are located in the
nucleus of an atom.
 The symbol for the
proton p+.
+
The Neutron
 Neutrons are neutral
subatomic particles, that
means they have no
charge.
 They are also located in the
Nucleus.
 The Symbol for the
Neutron is “n”.
ISOTOPES
Some atoms have more
neutrons then they have
protons. These atoms are called
Isotopes.
The Always Negative Electron
 Electrons are
negatively charged
subatomic particles.
 Their symbol is “e-”.
 Their location orbiting
around the nucleus.
-
The Next Level
 Electrons do not all
stay inside the nucleus
like the Protons or
Neutrons.
 Electrons orbit around
the nucleus in an
orbital.
The orbits
 Each orbital has a
specific number of
electrons it can hold.
 The orbitals fill from
the inside out.
Electrons
 The electrons on the outer
orbit are called valence
electrons.
Periodic Table
 You can use the periodic
table to figure out the
number of protons and
electrons an atom has.
Create your atom
 Pick and element off the
periodic table and draw a
picture of that atom.
The Stable Atom
 Atoms like to be stable.
 Only when an atom’s outer orbital is filled is it stable.
 Atoms will combine or react with each other to become
stable.
Types of Bonds
 A chemical bond is when two atoms join their electrons.
 There are four main types of bonds.
 Ionic Bonds
 Metallic Bonds
 Covalent Bonds
 Hydrogen Bonds
Ionic Bonds
 Some atoms are able to fill their outer orbital by giving up
or gaining an electron.
 In other words STEALING!
Ionic bonds
 When an atom gives up an electron the atom has
more protons then electrons and becomes
positively charged.
 When an atom gains an electron the atom has
more electrons than protons and becomes
negatively charged.
Ionic Compounds
 Positively charged atoms are attracted to negatively
charged atoms.
 When they come together they form an ionic compound.
Ions
 An atom that loses an electron has a positive charge, we
call these CATIONS.
 An atom that gains an electron has a negative charge, we
call these ANIONS.
Metallic Bonds
 When metal atoms bond they each kick out an electron.
 These electrons can float freely around each atom.
 Since the atoms are now positively charged they are
attracted to the sea of electrons and are bonded.
Covalent Bonding
 Some times atoms can share electrons to fill their
outer orbital.
 When they share their Valence electrons they
combine to form a molecule.
 Sharing = covalent bond
Hydrogen Bonds
 When hydrogens combine with other atoms the
Hydrogens stay slightly positive and the other atom stays
slightly negative.
 This is called polarity.
Hydrogen Bonds
 When two polar molecules come together the weakly
positive hydrogen will be attracted to the weakly negative
other atom.
 Water is the best example.