Periodic Trends Ionization Energy Worksheet With Answers printable pdf download

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periodic trends - ionization energy

Ionization describes the process in which an electron is removed from the valence shell of an atom. The amount

of energy required to remove the outer electron is known as the ﬁrst ionization energy. Successive electrons can be

removed as well. The following equations show the ﬁrst ionization and second ionization for the barium atom.

→

ﬁrst ionization:

+ e

second ionization:

+ e

The ionization energy varies depending on how strongly each electron is held to the nucleus. This attractive force is

related to three factors. First, the distance between the electron and the nucleus affects the electrostatic attraction: the

closer the electron the stronger the force. Second, the number of protons in the nucleus can affect the attraction of the

electrons. The more protons there are the greater the attraction. Finally, the ﬁlled energy levels between the nucleus and

the outermost electron are responsible for what is known as shielding.

Bohr’s model of a sodium atom: The

outer electron is attracted to the

nucleus by opposite charge. It is

also shielded by the inner electrons.

Directions: Use the information above to answer the following questions.

1. Use the graph to list the ionization energies for each of the noble gases (He, Ne, Ar, Kr, and Xe).  

2. Make a statement about the trend observed in ionization energy as you go down a group (from He to Xe). 

3. Make a list of the ionization energies for the elements in the second period (elements 3 – 10).  

lithium

boron

nitrogen

ﬂuorine

beryllium

carbon

oxygen

neon

4. What is the general trend in ionization energy as you move across the second period?  

5. Draw a diagram of neon and sodium atoms using the Bohr model (see above).

6. Use the models to explain why the ﬁrst ionization energy for sodium is so much lower than neon.  

7. There is a slight spike in the ionization energy for nitrogen, phosphorus, and arsenic. What do these elements all have

in common (hint: think orbital diagrams)?  

8. Draw an orbital diagram for nitrogen and oxygen. N:

9. Use your orbital diagrams to explain why it is easier to remove the outer electron of oxygen than the outer electron of

nitrogen.

10. Explain the large drops in ionization energy for Li, Na, and K from their preceding elements.

Periodic Trends Ionization Energy Worksheet With Answers