Congo, Conflict, Chemistry, and Cans: Day 7
Families on the Periodic Table Part I
I. Alkali Metals:
A. Properties:
- The alkali metals are the Group 1 elements (except
for hydrogen.)
- They all react with water.
B. Checking it out: Watch
https://www.youtube.com/watch?v=uixxJtJPVXk
(Alkali metals in water, accurate! Time 0:00 to 2:21)
1. Which alkali metal was the most reactive?
2. Does the reactivity of the alkali metals increase or decrease as you move down the periodic
table?
3. Alkali metals have _________ valence electron.
a) Draw the Lewis dot structures for Li, Na, and K.
b) Draw in the orbital diagrams below.
c) The alkali metals will (circle one) lose/ gain ___ valence electron when forming a
compound. They have an oxidation number of __________.
4. Would an alkali metal make a good replacement for tin in a tin can? Explain.
II. Alkali Earth Metals:
A. Properties
- The alkaline earth metals are the Group 2
elements.
Like the alkali metals, they are very reactive.
B. Checking it out: Observe the reactivity of two
alkaline earth metals in the lab.
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Watch: https://www.youtube.com/watch?v=aeb8H0WDuQo (Reactivity of Alkaline Earth
Metals) In each experiment, the metal is added to a mixture of water and phenolphthalein.
(Phenolphthalein is an acid/base indicator. It is used it here to indicate whether a chemical
change is occurring.)
Mg
Ca
Observations of metal in
water/ phenolphthalein
Watch: https://www.youtube.com/watch?v=tn2MHD_9DeM (Magnesium and Calcium reacting
with Hydrochloric Acid). The magnesium reacts in the first clip and the calcium reacts in the
second clip.
Mg
Ca
Observations of metal in
hydrochloric acid
Questions:
1. Which alkaline earth metal was most reactive in water?
2. Which alkaline earth metal was most reactive in acid (HCl)?
3. Were the alkaline earth metals more reactive in acid or water?
4. What did the phenolphthalein tell you about the reactions of magnesium and calcium with
water?
5. Does the reactivity of the alkaline earth metals increase or decrease as you move down the
periodic table?
6. Alkaline earth metals would have _________ valence electron.
a) Draw the Lewis dot structures for Be, Ca, and Ba.
b) Write the electron configuration (spdf notation) for:
Be:
Ca:
Ba:
c) The alkaline earth metals will (circle one) lose/ gain _____ valence electrons when
forming a compound. They have an oxidation number of __________.
9. Would an alkaline earth metal make a good replacement for tin in a tin can? Explain
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