Name: ___________________________________ Date: ________________________
 In the Bohr-Rutherford model of the atom, __________________ charged electrons orbit around a __________________ nucleus.
 The nucleus contains _________________ and ___________________, and makes up most of the mass of the atom.
 When an atom is forming an ion, it must fill it’s ___________level with electrons.
 Having a full valence level makes the atom more ___________ which means they have a lower ________________ .
RECALL - # Protons = atomic number
# Electrons = # Protons – the charge on the atom
# neutrons = atomic mass – atomic number
EXAMPLE: 9 F
19
1. Determine the number of protons, neutrons and electrons in Fluorine.
2. Draw a Bohr-Rutherford diagram of the fluorine atom, putting protons and neutrons in the nucleus, and electrons in the orbits. Two electrons fit in the first orbit, and eight in
the next two.
EXAMPLE: 20 Ca 2+ * This atom has a charge of 2+, it is called an ION. Draw a diagram.
40
1. Did Calcium gain or lose electrons to become an ion?

Name: ___________________________________ Date: ________________________
EXAMPLE: Draw the Bohr-Rutherford diagram of the element Chlorine (Cl), and then the
PRACTICE: ion of chlorine (Cl-).
1. Draw the following Bohr-Rutherford Diagrams, and calculate the ionic charge.
Ionic Charge = # Protons - # Electrons
Sodium (Na)
# protons =
# electrons =
Ionic Charge =
Sodium Ion (Na 1+ )
Calcium (Ca)
# protons =
# electrons =
Ionic Charge =
Calcium Ion (Ca 2+ )
Fluorine (F)
# protons =
# electrons =
Ionic Charge =
Fluorine Ion (F 1)
# protons =
# electrons =
Ionic Charge =
# protons =
# electrons =
Ionic Charge =
2. What are valence levels?
3. What are valence electrons?
4. Complete the worksheet “Forming Ions”.
# protons =
# electrons =
Ionic Charge =