Download Atomic structure

Ion Structure
What does an atom have to do to
become an ion around here???
Objectives
• To describe how an atom becomes an ion
• To determine the number of proton,
neutrons, and electrons in an ion
• To compare and contrast a cation and an
anion
How do ions form?
• The majority of atoms are
not happy
• In an attempt to become
happy (& chemically stable)
some atoms will give up
something.
• Looking at the atom, what is
easier to give up, protons,
neutrons, or electrons?
• Electrons are the easiest,
because they are on the
outside!
IONS
• Ions are atoms that have become
charged. Atoms become ions in two ways:
– They loose electrons and become +
– They gain electrons and become -
• Will ions have the same number of
protons?
• Yes!! The only thing that will change is the
number of electrons.Why?
• Electrons are the easiest particle to
move around
Cations & Anions
• Sodium (Na) will give up
an electron to become
stable.
• It will be postively charged
and called a sodium
cation
• Chlorine (Cl) will take an
electron
• It will become negatively
charged and be called a
chlorine anion
Sodium Cation
Sodium:
Protons: 11
Neutrons:
23 – 11 = 12
Electrons:
Neutral Atom:
11
Na Cation:
11-1 = 10
Take away= caTion
Chlorine Anion
Chlorine
Protons: 17
Neutrons:
35-17 = 18
Electrons:
Neutral Atom:
Anion
17 + 1 = 18
17
Add an electron = Anion
IONIC STRUCTURE
-1
Charge
To become negative, the atom
gained electrons
Atomic mass, atomic
number, the number of
Identify the following: protons, and neutrons
remain
the
same.
19
Atomic Mass:
Add an electron = Anion
F
Atomic Number:
9
# protons:
9
# neutrons
19 – 9 = 10
# electrons:
9 + 1e= 10
IONIC STRUCTURE
Determine the number of protons, neutrons, and
electrons in each of the following:
a)
b)
c)
Ca
Na
O
# pro: 20
# e-: 20 -2e = 18
# neu: 40 – 20 = 20
2+
+1
# pro: 11
# e-: 11 -1e= 10
# neu: 23-11 =12
-2
# pro: 8
# e-: 8 +2e= 10
# neu: 16 – 8 = 8