Lab Worksheet: It S a Chemical Attraction
Instructor’s Copy
Lab Worksheet: It’s A Chemical Attraction
Purpose: To observe the chemical properties of elements from two families.
Observations:
Record the NAMES and SYMBOLS of the members of the alkaline earth family.
1. Beryllium (Be)4. Strontium (Sr)
2. Magnesium (Mg)5. Barium (Ba)
3. Calcium (Ca)6. Radium (Ra)
Record the NAMES and SYMBOLS of the members of the halogen family (first four).
7. Fluorine (F)9. Bromine (Br)
8. Chlorine (Cl) 10. Iodine (I)
Data Table 1: Reactions of the alkaline earth family with sodium carbonate
Test tube / Solution tested / Observations with sodium carbonateA /
Magnesium nitrate
/ White precipitate formed (should be small particles, but students may not notice this)B / Calcium nitrate / White precipitate formed (particles should be a little bit bigger)
Hypothesize what will happen in tubes C & D /
White precipitate will form
C / Strontium nitrate / White precipitate formed (coarser)D / Barium nitrate / White precipitate formed (coarsest)
Data Table 2: Reactions of the halogen family with silver nitrate
Test tube / Solution tested / Reaction with silver nitrateA /
Potassium chloride
/White precipitate formed
Hypothesize what will happen in tubes B & C /White precipitate will form
B / Potassium bromide /Creamy (yellow-white) precipitate formed
C / Potassium iodide /Yellow precipitate formed
Related Questions/Conclusions:
11. Describe one chemical property of the alkaline earth family.
Ability to form a white precipitate when reacted with sodium carbonate
12. Describe one chemical property of the halogen family.
Ability to form a precipitate that goes from white to yellow as you go down the group.
13. When you look at the periodic table, the halogen family is labeled Group VIIA. What does the
number VII indicate?
That halogens have 7 valence electrons
14. The alkaline earth family is labeled Group IIA. What does the number 2 indicate about this family?
That alkaline earth family elements have 2 valence electrons
How many valence electrons do the following elements have?
15. carbon ___4__
16. phosphorus __5___
17. nitrogen __5__
18. List one characteristic of all members of the Noble Gas Family, Group VIIIA.
The are inert or they have 8 valence electrons or they are gases
19. Several drops of sodium carbonate are added to a solution of beryllium nitrate. Predict the results.
A white precipitate will form (might also put very fine particles)
20. Several drops of silver nitrate are added to a solution of sodium fluoride. Predict the results.
A very white precipitate (any mention of yellow would be wrong, but give partial credit if they
say a precipitate will form)