I.
Title:
II.
Purpose: To compare intensive and extensive properties of water
III.
Materials: 1) Beaker 2) Water 3) Thermometer 4) Hot Plate 5) Graduated Cylinder
IV.
Procedures:
V.
Data:
VI.
Intensive and Extensive Properties
1) Fill a beaker with 100 mL of water. 2) Fill a beaker with 400 mL of water. 3) Set both beakers on hot plates to boil. 4) Record the boiling points of both beakers in °C. 100 mL of water
400 mL of water
Boiling Point (°C)
95
99
Time it takes to boil (s)
395
810
Analysis & Conclusion: 1) Temperature is an intensive property of matter because the mass of the water did not affect the boiling point. 2) The amount of energy absorbed (determined by the time it takes water to boil) is an extensive property of matter because the mass of the water affected the time it took to boil. 3) Two additional extensive properties of matter are mass and volume. 4) Two additional intensive properties of matter are melting point and freezing point. 5) Conduct an experiment to show whether density is an intensive or extensive property of matter. Procedures: 1. Determine the mass of two beakers using a balance. 2. Fill two beakers, one with 100 mL of water, the other with 200 mL. 3. Use a balance to calculate the mass of the beaker with water, and then subtract the mass of the used beaker on its own from the total mass. 4. Calculate densities and compare results. Results 100 mL of water had a calculated density of 0.99 g/mL 200 mL of water had a calculated density of 1.02 g/mL Conclusions Because the accepted value of the density of water is consistently 1 g/mL, we believe that our measurements were both imprecise and inaccurate because of measurement error. Thus, we conclude that mass does not affect the density of water, making it an intensive property of mater.
I.
Title:
II.
Purpose:
Separating Mixtures To separate out a mixture of the following pure substances: iron, sulfur and salt
III. Materials: 1) Paper Plate 2) Plastic Dish 3) Mixture Sample 4) Magnet 5) Water 6) Beaker 7) Funnel 8) Filter Paper 9) Flask 10) Hot Plate IV. Procedure: 1) Mix samples of sulfur, iron, and salt into one mixture. 2) Using a magnet, isolate all iron from the mixture. 3) Add 20 mL of water to the remaining sulfur-salt mixture. 4) Filter out the sulfur from the mixture. 5) Boil away the water from the remaining saltwater mixture to isolate the salt. V.
Data:
Observations
VI.
Nearly all the iron of the original Sulfur-IronSalt mixture was separated out by magnetism. After adding water to the sulfur-salt mixture and then filtering it, all but a little sulfur was filtered out. Boiling out all of the water of the remaining salt-water mixture left the gritty remains of pure salt.
Analyze and Conclude: 1) The components of this mixture were sulfur, iron, and salt. 2) This mixture was a heterogeneous mixture. 3) I did not know the percent c omposition of the mixture. 4) Knowing the percent composition would have allowed me to guarantee whether or not complete separation had occurred by comparing the original percent composition with the resulting percent composition.
H
I.
Title: Constructing a Model
II.
Purpose: To understand how scientists make inferences about atoms without touching or seeing them
III.
Materials: 1) Closed Container 2) Various Objects
IV.
Procedures:
V.
Data:
3) Balance
1) Close four containers filled with various objects. 2) Guess the objects’ quantity, mass and quality by any means provided that the container remains closed. 3) Open the container, and without looking, guess again the objects’ quantity, mass and quality. 4) Now looking into the container, record the true quantity and quality of the objects. Use a balance to determine the mass. A) Closed Container
Group Number
Number of Objects
Mass of Objects (g)
Kind of Objects
1
11
40
Metallic
2
10
30
Metallic
3
9
50
Nonmetal
4
10
20
Metallic, Coins
B) Open Container without Looking Group Number 1
Number of Objects 11
Mass of Objects (g) 40
2
10
35
3
13
60
4
8
25
Kind of Objects fly paper, metal nuggets, metal sheet, little coin, medal keychain, lego-man, fake flower, tech dech dude, little stuffed toy rubix cube,toy dolls, bottle cap, paper slip, die, plastic ring seashell, bottle cap, necklace, hairpin, toothpick, bracelet, coins
C) Open Container with Looking
VI.
Group Number 1
Number of Objects 13
Mass of Objects (g) 66
2
15
53.5
3
13
90.4
4
8
28
Kind of Objects pin, nut, stone, small medal, fishing weight, butterfly, fly paper, shirt pin, large medal, tin foil, large bean, weight, Coke accessory screw, stuffed toy, barnacle, sponge, tech deck dude, key chain, lego-man, fake flower, various toys, tin foil, smooth stone, coin, paper clip marbles, rubix cube, metal cap, die, doll, toy, paper slip, plastic ring Seashell, bracelet, hairpin, cap, match, coin
Analysis and Conclusion: 1) I was able to gather only very little data from the closed container. The conjectures I made as to the number, weight, and kind of objects were based upon classifications of sounds and sensations, resulting from shaking the container. In short, I had to use reasoning, not just seeing to speculate as to what was in the container. 2) As more of my senses gained access to the contents of the container, the more the amount of accurate data increased. Feeling, instead of just hearing the objects in the container, for example, increased the data I had for the number and quality of objects. Actually seeing the objects further increased the amount of data for my experiment. Gradually, my data ceased to be guesses and became facts. 3) Thus, this experiment is illustrative of the way scientist gather data about atoms. Facts about atoms are not immediately apparent to our senses. In 19th century, scientists reasoned to facts about atoms by indirect knowledge and experiments, facts which became more certain as the evidence converged. One example is the discovery of the proton. As this experiment had me reach blindly to try to determine what objects were in the container, so Rutherford, without actually seeing a nucleus, reasoned to its existence in the atom from his gold foil experiment. That 1 in 8000 positive alpha particles returned instead of passing through the foil when bombarded against it, indicated to Rutherford that a small positive entity he called the “nucleus� caused the particles to return. This is not dissimilar from the way this experiment allowed us to know that there were toy dolls in Container #3, without ever looking at them.
I.
Title: Comparing and Calculating Densities
II.
Purpose: To use the physical property of density to identify unknown substances.
III.
Materials: 1) Density Blocks 2) Beaker 3) Water 4) Balance
IV.
Procedures:
V.
Data:
1) Fill a beaker with water. 2) Predict whether each density block will sink or float when placed in water. 3) Place each density block in the water and record whether it sank or floated. 4) Measure the density blocks to calculate the volume. 5) Use a balance to determine the mass of each density block. 6) Calculate the density of each block. 7) Matching the densities with their given corresponding substances, identify the substances of each of the density blocks.
Density Blocks 1 2 3 4 5 6 7 8 9
Density Block 1 2 3 4 5 6 7 8 9 VI.
Mass (g) 15 8 128 20 44.5 144.3 14.2 138 23
A) Prediction (Sink or Float) Float Float Sink Float Sink Sink Float Sink Sink
Length (cm) 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5
Width (cm) 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5
B) Height (cm) 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5 2.5
Observation (Sink or float) Float Float Sink Sink Sink Sink Float Sink Sink
Volume (cm3) 15.625 15.625 15.625 15.625 15.625 15.625 15.625 15.625 15.625
Density (g/cm3) 0.96 0.51 8.19 1.28 2.85 9.24 0.91 8.83 1.47
Substance Polypropylene Pine Steel Acrylic Aluminum Copper Oak Brass PVC
Analysis and Conclusion: 1) Polypropylene, pine, and oak were less dense than water. Steel, acrylic, aluminum, copper, brass, and PVC were more dense than water. 2) The fact that the volume was the same for each block indicated that an increase or decrease of mass yields a proportional increase or decrease of density.
3) I identified each the unknown substance by matching the densities with their given, corresponding substances. 4) Nearly all the unknown substances’ densities fit into the ranges for a known substance’s density on the chart. The few that did not fit in were, however, very close to the given ranges. These discrepancies were probably due to either measurement or rounding error.
Periodic Table of Elements: featuring top Google Image results
Atomic Orbital Drawings
I.
II. III. IV.
V.
VI.
Title: The Mole Purpose: To identify four unknown elements, each of which has one mole of atoms Materials: 1) Mole Samples – “A” through “D” 2) Balance Procedures: 1) Make qualitative observations of each sample. 2) Using a balance, determine the mass of each sample and the molar mass of the samples’ elements. 3) Using the equation (Mass/# of atoms), calculate the actual mass of 1 atom for each sample. 4) Using the molar mass of each sample, identify their respective elements. Data: Sample Description Mass of 1 Molar Mass Actual mass Identity of mol (g) (g/mol) of 1 atom (g) the Elements A Silvery, shiny 65.25 65.25 1.084x10-22 Zinc and heavy, long B Silvery and 27 27 4.484x10-23 Aluminum shiny, lightweight, long C Dark, slivery, 56 56 9.299x10-23 Iron short D Bronze63.5 63.5 1.054x10-22 Copper colored, shiny, heavy, short Analyze and Conclude: 1) Elements with one mole of atoms have different masses because the average atomic mass of atoms of those elements differ. 2) If each element had 2 moles of atoms, the masses of the sample elements would be: A = 130.5 g, B = 54 g, C = 112 g, D = 127 3) Just by looking at the samples, I determined element A to have atoms with the largest volume. 4) If its mass was exactly one-half, each element would likewise have one-half a mole. 5) If it had 3 moles, the number of each atom of the sample elements would be 1.807x1024.
a. Energy levels are like rungs on a ladder because there are only certain particular energy values that the electrons can have in atoms, and all other values are forbidden. In the same way, you can’t stand in between the rungs of a ladder; your foot must be on a rung. b. The frequency and wavelength of an electromagnetic wave are inversely related. Waves that vibrate faster have shorter wavelengths. Waves that vibrate more slowly have longer wavelengths. c. A blue wave has more energy than a red wave because red light (at 700 nm) is at the longer wavelength end, and therefore the low energy end. A blue wave (at 450 nm) is at the shorter wavelength, and therefore the high energy end. d. The Law of Conservation of Energy tells us that energy is neither created nor destroyed; so the energy lost by an electron must exactly equal the energy emitted by an atom.
e.
I.
Title: Designing Your Own Periodic Table
II.
Question: Can you design your own periodic table using information similar to that available to Mendeleev?
III.
Materials: 1) Periodic Table
IV.
Procedures:
V.
Data:
2) Index Cards
1) Write down the information available for each element on separate index cards. The following information ins appropriate: a letter of the alphabet (A, B, C ect.) to identify each element; atomic mass; state; density; melting point; boiling point; and any other readily observable physical properties. Do not write the name of the element on the index card. But keep a separate list indicating the letters you have assigned to each element. 2) Organize the cards for the elements in a logical pattern as you think Mendeleev might have done. A)
My Cards
B)
Organize #1
The information given in the first set of cards was insufficient to construct a periodic table. Having merely the atomic mass and several other properties to organize 20 of the 118 elements, it was impossible to make more than a column or two of straight lines of descending atomic mass. Thus, no suitable periodic organization of the given unknown elements was possible for my first organization. However, the addition of electron configuration to the information in the second set allowed for proper periodic organization.
C) 3
4
5
6
7
8
Organize #2
1
2
9
10 11 12 13 14 15 16 17 18
2
G
L
R
3
H
M
S
4
I
N
5
J
O
6
K
P
1
7
C
T
A
Q
F
Key: A – Bromine F- Rhenium J- Rubidium N-Calcium R- Boron VI.
E
D
B
B- Iridium G- Lithium K-Cesium O-Strontium S-Aluminum
C- Iron H- Sodium L- Beryllium P-Barium T-Gallium
D- Neon E- Copper I- Potassium M-Magnesium Q- Radium
Discussion: 1) a. Atomic masses are given instead of atomic numbers because Mendeleev did not know the atomic numbers of the elements he was dealing with when he organized them. Protons had not yet been
discovered. Rather, Mendeleev used atomic mass, which is why we are given this data instead of atomic numbers. b. By looking at the modern periodic table, I can identify each element by name by matching its atomic mass to its respective name. 2) My periodic table has 18 groups of elements and 7 periods. 3) I would predict the missing elements in Groups 1 and 2 to be solid metals with very high boiling points, relatively high melting points, high reactivity, and low density (between 1 and 2 g/cm3). I would predict the missing elements in Groups 8 and 12 to be metals with higher density, high melting points, and high boiling points. I would predict missing Group 13 elements to be solid, with metallic properties, high melting and boiling points and lower density than Group 8 elements. I would predict missing Group 16 elements to be liquids or gases, to have low melting and boiling points, low density, and to exhibit notable reactivity. I would predict Group 18 elements to be gases, to have very low density, boiling points, and melting points, and to be generally unreactive. Lastly, I would predict any potential elements in the group or period of F and B to be solid metals with high density, melting points, and boiling points.
I. II. III. IV.
V.
Title: Observing Chemical Elements Purpose: To compare and contrast various elements on the periodic table through observation Materials: 1) Various Chemical Elements Procedures: To conduct the lab, the chemist observed and researched a collection of 23 different elements. The act of observation the elements consisted in recording visual characteristics alone; however, the clear containers of each element were permitted to be shaken. The act of researching consisted in recording the chemical symbol, group number, group name, period, block, atomic mass, atomic number, electron configuration, reactivity, whether a metal, nonmetal or metalloid, and uses of each element. Data: Metal? Nonmetal? Metalloid?
Element Name
Chemical Symbol
Group Number
Group Name
Period
Block
Atomic Mass
Atomic #
Electron Configuration
Characteristics
Reactivity
Uses
Calcium
Ca
2
4
s
40.08
20
[Ar]4s2
white solid
Li
1
2
s
6.94
3
[He]2s1
silvery solid
Barium
B
2
6
s
137.33
56
[Xe]6s1
dark solid
bones and shells lithium batteries fireworks
Lead
Pb
14
6
p
207.2
82
[Xe]4f145d106s26p2
Ni
10
4
d
58.69
28
[Ar]3d84s2
lead-acid batteries nickels
metal
Nickel Zinc
Zn
12
4
d
65.39
30
[Ar]3d104s2
reactive
galvanization
metal
Mercury
Hg
12
6
d
200.59
8
[Xe]4f145d106s2
dark, shiny solid mildly silvery solid grayish-white solid silvery liquid
very reactive very reactive very reactive less reactive reactive
metal
Lithium
reactive
thermometers
metal
Cadmium
Cd
12
AlkalineEarth Metals Alkali Metals AlkalineEarth Metals Boron Group Transition Metals Transition Metals Transition Metal Transition Metal
5
d
112.41
5
[Kr]4d105s2
shiny solid
reactive
metal
Magnesium
Mg
2
AlkalineEarth Metals
3
s
24.31
12
[Ne]3s2
shiny solid
very reactive
nickelcadmium batteries fire-starter
metal metal
metal
metal
Bromine
Br
17
Halogens
4
p
79.90
35
[Ar]3d104s24p5
clear liquid
Cobalt
Co
9
4
d
58.93
27
[Ar]3d74s2
Aluminum
Al
13
3
p
26.98
13
[Ne]3s23p1
Copper
Cu
11
4
d
63.55
29
[Ar]3d104s1
Bismuth
Bi
15
6
p
208.98
83
[Xe]4f145d106s26p3
Silver
Ag
11
5
d
107.87
47
[Kr]4d105s1
Carbon
C
14
2
p
12.01
6
[He]2s22p2
shiny, bubbled solid shiny, grayish solid shiny, brown powder silvery, shiny solid silvery shiny powder black powder
Antimony
Sb
15
5
p
121.76
51
[Kr]4d105s25p3
Tungsten
W
6
6
d
183.84
74
[Xe]4f145d46s2
Chromium
Cr
6
4
d
52.00
24
[Ar]3d54s1
shiny, silvery solid dark, shiny powder tarnished solid
Sulfur
S
16
3
p
32.07
16
[He]3s23p4
yellow powder
Silicon
Si
14
3
p
28.09
14
[Ne]3s23p2
sparkling solid
Iron
Fe
8
4
d
55.85
26
[Ar]3d64s2
dark solid
Tin
Sn
14
Transition Metals Boron Group Transition Metal Nitrogen Group Transition Metals Carbon Group Nitrogen Group Transition Metals Transition Metal Oxygen Group Carbon Group Transition Metals Carbon Group
5
p
118.71
50
[Kr]4d105s25p2
shiny solid
VI.
Conclusion:
very reactive less reactive reactive
daguerreotypes
nonmetal
prostheses
metal
aluminum foil
metal
reactive
copper wire
metal
less reactive reactive
lead-free solders silverware
metal
reactive
diamonds
nonmetal
less reactive less reactive less reactive more reactive reactive
matches
semiconductor
electron microscopes electroplating
metal
detergents
nonmetal
computer chips
semiconductor
iron bars
metal
tin cans
metal
less reactive reactive
metal
metal
This lab has greatly aided the chemist in coming to a better comprehensive understanding of the elements of the periodic table. By not only researching into the chemical nature of these elements, but observing them with the eyes, the chemist is now considerably more familiar with these elements. It is indeed remarkable how many uses each element has, and yet they remain unknown under our very noses. By researching the uses of these elements, the chemist has come to a much more appreciative view of how these elements make up the technologies we often take for granted.