How elements combine
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I can explain what an ion is
and how an ion forms
Science Standard:
Use the periodic table as a model to predict the
properties of elements based on patterns of the
electrons in the outermost energy level of atoms
Elements, Atoms, and Ions
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The Atom
An atom consists of a
nucleus
 (of protons and neutrons)
 electrons in space about the nucleus.

Electron cloud
Nucleus
the positive (+) particle is called a
proton
+
the negative (-) particle is called an
electron
the particles
that make up atoms
have either
positive or negative charge
+
+
+
+
+
positive and negative are opposites
+
+
they cancel each other out
+
+
+
net charge = zero
+
+
NEUTRAL ATOM
+
+
+
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In order to understand
what ions are,
we need to know that…
in an atom,
protons ( + ) are in
the center
and electrons ( )
are on the outside
+ ++
+ +
only electrons ( )
can be added
or taken away
+ ++
+ +
this is an atom with
5 electrons and
5 protons
+ ++
+ +
the atom is neutral
net charge = zero
+ ++
+ +
5 (-) and 5 (+) = zero charge (neutral)
+ ++
+ +
+ ++
+ +
+ ++
+ +
Charged Atom
ION
charge = ?
+ ++
+ +
charge = 1- (one minus)
+ ++
+ +
+ ++
+ +
Charged Atom
ION
+ ++
+
charge = ?
2+ (two plus)
+ ++
+ +
WHEN REMOVING ELECTRONS
WHEN REMOVING ELECTRONS
THE RESULTING CHARGE IS POSITIVE
WHEN REMOVING ELECTRONS
THE RESULTING CHARGE IS POSITIVE
neutral
1+
WHEN ADDING ELECTRONS
WHEN ADDING ELECTRONS
THE RESULTING CHARGE IS NEGATIVE
WHEN ADDING ELECTRONS
THE RESULTING CHARGE IS NEGATIVE
neutral
2
An atom with positive or negative charge
is called an
drum roll
ION
Atoms without charge are called ATOMS
Atoms with positive or negative charge
are called IONS
Notice that ONLY the number of e- changes
(Only electrons are added or subtracted)
The number of protons in an
Atom NEVER changes
(why?)
Ions are what produces color in
a plasma ball and the aurora
borealis
Ions in the human body
/
ions make up the salt you put on French fries
ions are required for your brain to function
(ions allow you to see and understand this presentation)
ions are an essential ingredient in soap
ions are required for cellular respiration C6H12O6 + O2
CO2 + H2O
ions make up acids and bases
ions keep your blood functioning
ions make up the salt you put French fries
ions are required for your brain to function
(ions allow you to see and understand this presentation)
ions are an essential ingredient in soap
ions are required for cellular respiration C6H12O6 + O2
ions make up acids and bases
ions keep your blood functioning
CO2 + H2O
Metals combine with non-metals
Metals lose electrons to non-metals
They then attract because their charges will be opposite.
PREDICTING ION CHARGES

metals (Mg) lose electrons ---> positive ion

nonmetals (F) gain electrons ---> negative ion
An atom with positive or negative charge
is called an
drum roll
ION
WHEN REMOVING ELECTRONS
WHEN REMOVING ELECTRONS
THE RESULTING CHARGE IS POSITIVE
WHEN REMOVING ELECTRONS
THE RESULTING CHARGE IS POSITIVE
neutral
1+
Positively charged ion
Cation
WHEN ADDING ELECTRONS
WHEN ADDING ELECTRONS
THE RESULTING CHARGE IS NEGATIVE
WHEN ADDING ELECTRONS
THE RESULTING CHARGE IS NEGATIVE
neutral
2
Negatively charged ions
Anions
Section A: Complete the chart using a periodic table to help you.
Charges on Common Ions
-3
+1
-2
-1
+2
By losing or gaining e-, an atom has same number of e-’s
as nearest Group 8 atom and can pretend to be like a
noble gas!
Opposites Attract!
Opposites make a compound
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