Name ________________________________________________
Physical Science
Date _______________
Mrs. Hanna
Introduction:
The structure of the periodic table is such that elements with similar properties are aligned
vertically in columns called “groups”. This leads to smoothly varying trends in properties such as
ionization energy and atomic radius as one moves
both down the periodic table within a specific
group or as one moves horizontally along a given
period within the table. The reactivities of the
elements also follow well-defined trends both within
groups and across periods. In this experiment, you
will explore these trends in reactivity.
Elements in the periodic table are organized
by increasing atomic number. As atomic numbers
increases, so does the number the electrons.
Electrons, and specifically valence electrons, are
important in determining how an atom interacts
with other atoms. The elements in a group have
similar properties because they have the same
number of valence electrons which are found in similar electron configurations. The elements in the
periodic table are divided into categories. This system is useful for finding a particular element and
also for making predictions about an element based on its position in the table.
Part 1: Trends in the Properties within Groups
While watching the video on the activity of Alkali Metals record your observations below
Group 1 metals: Alkali
Metal
Observations: Reaction in Water
Lithium
Sodium
Potassium
Cesium
Alaki metals reacting in water
http://www.youtube.com/watch?v=uixxJtJPVXk
While watching the video on the activity of Magnesium and Calcium records your observations below.
Group 2 metals: Alkaline Earth
Metal
Observations: Reaction in Water
Magnesium
Calcium
Reactivity of Magnesium and water
http://www.youtube.com/watch?v=u_1uLP30uxY
Reactivity of Calcium and water
http://www.youtube.com/watch?v=i-rFsFwdkTU
Questions:
1) Explain why you see a difference in the reactivity of the two alkaline metals, magnesium and
calcium, with water.
2) What is the trend going down the first group of Alkali metals?
3) What is the trend going down the first group of Alkaline metals?
4) What is the trend going across from group one to group two?
1.
Part 2: Activity Series of Some Metals in HCl
Obtain a small piece of each of the metals in the data table below. Place each metal in a small separate test tube.
Add a small amount of dilute HCl to the test tube, just enough to cover the sample.
https://www.youtube.com/watch?v=l0U7VDSxGHk (results at 2:30)
Metal
Observations: Reactions with HCl
Magnesium
Aluminum
Copper
Zinc
Questions:
1) List the 4 metals from your data table from most reactive to least reactive. Use data from your lab to support your
answer.
Most reactive
1)
2)
3)
4)
Least reactive
2) What group number is each of these metals in:
Magnesium: _________
Aluminum: _________
Copper: __________
Zinc: __________
3) What is the trend of reactivity as you go across the table from left to right? Use the data table information above
to help you.
Questions (use the periodic table) :
1) Do your results support your estimate? Explain.
2) Describe the trend you saw with density.
3) What happens to atomic mass when going down each group of the periodic table? When going across each
period?
4) What happens to atomic radius when going down each group? When going across each period?