Name _________________________________
CH 5.3 - Periodic Trends WebQuest PART I
There is a .pdf version of this assignment on my blog. Please utilize the online version to link the webpages in order to avoid typing in
the addresses. Reminder: columns on the periodic table are called families or groups and rows are called periods
Atomic Radius (pages 174-175)
Using your text, please answer the following:
1.
Can the radius of an atom be measured directly? _________________
2.
In what unit is atomic radius usually measured? _________________
3.
Define Atomic Radius:
Go to the following website:
http://www.webelements.com/periodicity/atomic_radius_empirical/bar_chart.html
4.
Look at the graph. What is on the X Axis ? _____________________
5.
What is on the Y Axis (include units)?________________________
6.
The colors on the graph represent rows on the periodic table.
In a complete sentence, answer - What appears to be the trend in atomic radius as you move from left to right in a row?
In a complete sentence, answer - What appears to be the trend in atomic radius as you move down a column?
7.
8.
Using your text, please answer the following:
a.
What is the general trend for atomic size within a group/family from top to bottom?
b.
What two variables affect atomic size within a group?
c.
What is the general trend in atomic size from left to right within a period?
Use the graph to the right to answer the following:
a.
Determine which metal has an atomic radius of 238 pm?
b.
Is an atom of barium, atomic number 56, smaller or
larger than an atom of cesium (Cs)?
c.
Which has a larger atom, helium or argon?
d.
Which has a larger atom, potassium or argon?
Teacher Checkpoint_________________________________
Ions and Ionization Energy (pages 177-181)
Using your text, please answer the following:
9.
What is an ion?
10.
How are ions formed?
13.
11.
An ion with a positive charge is called a(n)
______________________.
12.
An ion with a negative charge is called
a(n)______________________.
Define Ionization Energy:
Go to the following website:
http://www.webelements.com/periodicity/ionisation_energy_1/graph.html
14.
Look at the graph. What is on the X Axis ? _____________________
15.
What is on the Y Axis (include units)?________________________
16.
The colors on the graph represent rows on the periodic table.
In a complete sentence - What appears to be the trend in ionization energy as you move from left to right in a row?
In a complete sentence - What appears to be the trend in ionization energy as you move down a column?
17.
Now click on the word cylinders at the upper left. A new graph will appear. Click on the different versions of the data.
Which graph is easiest for you to interpret?_________________
18.
Using your text, please answer the following:
19.
a.
Why does ionization energy tend to decrease from top to bottom within a group?
b.
Why does ionization energy tend to increase as you move from left to right across a period?
Use the graph to the right to answer the
following:
a.
Which element in period 2 has the lowest first
ionization energy?
b.
Which element in period 3 has the lowest first
ionization energy?
c.
What is the group trend for first ionization energy
for noble gases and alkali metal?
d.
If you drew a graph for second ionization energy,
which element would you have to omit? Explain.
Teacher Checkpoint________________________________
Ionic Size (pages 176-177)
20.
Using Figure 5-16 on page 175 and figure 5-17 on p. 176 to answer the following:
a.
Look at Figures 5-16 & 5-17 and compare the size of the ion versus the neutral atoms. These are represented with the spheres
in the picture. Neutral atom size is fig.5-16 and ionic size is fig 5-17. Also look at figure 5.18 on p. 177. Describe how the size
changes when an atom forms a cation and when an atom forms and anion.
b.
Graph Atomic Number vs. Ionic Radii.
c.
How do the ionic radii vary within a group of
metals?
e.
How do the ionic radii vary within a group of
nonmetals?
f.
Describe the shape of the portion of a graph
that corresponds to one period.
g.
Is the trend across a period similar or different
for periods 2,3,4 and 5?
21.
Use your text to answer the following:
a.
Do metallic elements gain or lose electrons? _________________What charge ions do metals tend form?
b.
Do nonmetallic elements gain or lose electrons? _______________What charge ions do nonmetals tend to form?
c.
What happens to the radius when an atom forms a cation (loses electrons – becomes positively charged)? Why?
d.
What happens to the radius when an atom forms an anion (gains electrons – becomes negatively charged)? Why?
Teacher Checkpoint______________________
Electronegativity (pages 184-185)
Using your text, please answer the following:
22.
Define Electronegativity:
23.
Why do the noble gases not have an electronegativity number in fig. 5-23 on page 184?
Go to the following website:
http://www.webelements.com/periodicity/electronegativity_pauling/
Scroll down to the graph, click on the different types of graphs listed on buttons at the bottom to see the various representations of
differences in electronegativity. You may also click on “line graph” on the top left to view that version of the relationship.
24.
Which graph helps you to best identify the trends in electronegativity?______________________
25.
In a complete sentence - What appears to be the trend in electronegativity as you move from left to right in a row?
In a complete sentence - What appears to be the trend in electronegativity as you move down a column?
26.
What element has the highest electronegativity?
27.
What element has the lowest electronegativity?
Using your text, please answer the following:
28.
What is the trend for electronegativity within a group?
29.
What is the trend for electronegativity within a period?
Using your text – page 184 - summarize all trends on the chart below.
Teacher Checkpoint_________________