SC5a Formation of Ions
1. Use the words below to complete sentences a-e.
charge
anions
positively
gain
negatively
atom ionic
lose
atoms
cations
a. An ion is the name for an ___________ or group of ____________ that has lost or
gained electrons and has a _____________ .
b. Metal atoms ____________ electrons to form ________________ charged ions.
c. Non-metal atoms ____________ electrons to form ________________ charged ions.
d. Positive ions are known as ___________ and negative ions are called ____________ .
e. Positive and negative ions can form a strong attraction to one another which is called
an ___________ bond
2. Complete the table to show what happens when these atoms form ions.
Number of electrons
Atomic
symbol
Electron
config.
Li
2.1
Na
2.8.1
K
2.8.8.1
Mg
2.8.2
Ca
2.8.8.2
O
2.6
S
2.8.6
F
2.7
Cl
2.8.7
Metal or
non-metal?
In the
atom?
Lost or gained?
How many?
In the
ion?
Formula
of ion
SC5a Formation of Ions
3. Complete the diagrams to what happens to the electrons in magnesium and oxygen
atoms when they react with each other. Repeat this for potassium and fluorine atoms.
 Draw dots for electrons in the metal atoms
 Draw crosses for electrons in the non-metal atoms
 If an electron is transferred from atom to another, draw the electron in the new
location as it was (i.e., dot or cross) in the original atom.
Atom: Mg
Atom: O
Atom: K
Atom: F
Ion: Mg2+
Ion: O2-
Ion: K+
Ion: F-
4. The image below represents a specific type of ion.
137
56
Ba
2+
Explain what each piece of information (i-iv) tells you about the ion. In your answers
include details about the number of protons, neutrons and electrons in this ion.