Homework #16

2SAS #26- 34

26. Metallic elements are more likely to lose electrons.
27. Noble gas elements are unreactive and chemically inert. 
28.
a. cation.
b. cation.
c. anion.
d. cation.
e. anion. 
f. cation
g. cation.
h. anion.
29.

a. Copper metal ions because copper metals form cations, and the only difference between copper metal and copper (II) ions is the absence of 2 electrons.


30. 156+254=410
      410/2=205; 205 pm. 
      The diameter of a calcium ion (Ca^2+) = 205 pm.
31. a. 
Chemical cause: oxidization or rusting results in a change in color.
Physical cause: painting a substance results in a change in color. 
b.
Chemical cause: combustion causes a change in temperature.
Physical cause: boiling a substance will raise the temperature.
c.
Chemical cause: the reaction of HCl and Cu causes the formation of a gas. 
Physical cause: after boiling, water will become a gas (water vapor) as it evaporates. 

32.
a. Bromine (Br). 
b. Silicon (Si).

33.
In analyzing our Snake River data to solve the fish-kill mystery in Unit 1, we had to compare mass changes among the different substances we tested for with the normal masses. We used our knowledge of properties of the different substances to create legitimate and logical hypotheses.


34. Argon would have had to be placed after potassium and cobalt would have had to be placed after nickel, in order to be accurate in Mendeleev's original periodic table. 
2SBS:
1.
Atmosphere: nitrogen, oxygen, neon, and argon. 
Hydrosphere: water and dissolved minerals. 
Lithosphere: petroleum and metal-bearing ores. 

2. a. 
The crust: top 40km: the thin band of soil and rock containing major raw materials needed to build all manufactured objects. 
The mantle: 40-2900km: the middle layer of the lithosphere. 
The core: 2900km: Earth's center: extremely hot.
b. 
The crust serves as the main storehouse of chemical resources used in manufacturing consumer products. 

3. a. Mexico.
b. Japan.
c. China. 
4. China produces the largest masses of the eight listed resources. 
5. Ores are naturally occurring rocks or minerals that can be mined and from which are profitable to extract a metal or other metal. Minerals are naturally occurring solid compounds containing the element or group of elements of interest. 

6. -the quantity of useful ore found at the site.
-the percent of metal in the ore. 
-the type of mining and processing needed to extract the metal from its ore. 
-the distance between the mine and metal-refining facilities and markets.
-the metal's supply-versus-demand status. 
-the environmental impact of the mining and metal processing. 
7. Maybe the gold had replenished after 100 years and demand for gold was high. 
8. Useful ore refers to the amount, usually as a percent, of the desired mineral being mined.

Homework #15

13. a. A horizontal row is also a period, with elements listed in order of increasing atomic numbers.
    b. A vertical column is a group, that contains elements with similar properties.

14. Sodium (Na) and Potassium (K).

15. a. The noble gases are located on the far right side of the periodic table.

    b. Noble gases are unreactive. 
    c. Noble gases are chemically inert. 

16. a. MgF2
    b. GaP

17. 

Potassium is right between sodium and rubidium on the periodic table:

98+39=137
137/2=68.5

18. I would expect the boiling point of chlorine to be lower than that of iodine. From what I have observed, I believe that elements with higher atomic weights have higher boiling points than those with lower atomic weights. Chlorine has a lower atomic weight (35.45) than iodine (126.90), so, chlorine must have a lower boiling point. 

19. 

Completed chart:

20. 

a. 4 protons, 4 or 5 neutrons, 4 electrons.
b. 7 protons, 7 or 8 neutrons, 7 electrons.
c. 10 protons, 10 or 11 neutrons, 10 electrons. 

21. Although protons are positive, when an atom forms an ion, it either loses or gains electrons. Since a lead ion with a 2+ charge was formed, the atom must have lost two electrons.

22. 

a.
Carbon: 6+6=12, or 6+7=13; 12 or 13
Calcium: 20+21=41; 41
Platinum: 78+117=195; 195
Uranium: 92+146=238; 238

b. Carbon has two isotopes in the table. 

23. No, the discovery of a new element would not be justified by only its mass number. It would be more helpful to know either the atomic weight or atomic number in order to be able estimate physical and chemical properties of the element and its probable spot on the periodic table. An element's mass number does not provide enough information to justify its existence. 

24. The mass of an electron is about 1/2000 the mass of a proton or a neutron. Because of its minuscule weight, it is insignificant, and not used to calculate the mass number of an atom.

25. 

Completed Chart:

Homework #14

2SAS #1-12 


1.
 a. Physical property.
b. Chemical property. 
c. Chemical property.
d. Physical property.

2. 

a. Physical property.
b. Physical property.
c. Physical property.
d. Chemical property.

3. 

a. Chemical change.
b. Physical change.
c. Chemical change.
d. Physical change.

4. 

a. Chemical change.
b. Chemical change.
c. Physical change.
d. Physical change.

5. 

a. The gases from the atmosphere react with the inner layer of the apple, causing decay.
b. The energy from flashlight batteries are drained, and the reaction is reversed to extract electricity from the battery.
c. The clothing still maintains its original form, but the oils are removed.
d. The mixture will suspend with the container, and a chemical reaction fails to occur. 

6. 

1. Preheat oven to 350 degrees. In a small bowl, whisk together the flour and baking soda; set aside. In the bowl of an electric mixer fitted with the paddle attachment, combine the butter with both sugars; beat on medium speed until light and fluffy. Reduce speed to low; add the salt, vanilla, and eggs. Beat until well mixed, about 1 minute. Add flour mixture; mix until just combined. Stir in the chocolate chips.
2. Drop heaping tablespoon-size balls of dough about 2 inches apart on baking sheets lined with parchment paper.
3. Bake until cookies are golden around the edges, but still soft in the center, 8 to 10 minutes. Remove from oven, and let cool on baking sheet 1 to 2 minutes. Transfer to a wire rack, and let cool completely. Store cookies in an airtight container at room temperature up to 1 week.

7. 

a. metals.
b. nonmetals.
c. nonmetals.
d. metals. 

8. 

a. metal.
b. metalloid.
c. nonmetal.
d. metal.

9. 

1) Silicon: Si
2) Arsenic: As 

10. 

a. it would shatter (brittle).
b. it would flatten (malleable).
c. it would shatter (brittle.
d. it would flatten (malleable). 

11. Nonmetals do not conduct electricity and are not malleable. Nonmetal wiring therefore couldn't conduct electricity. 

12. 

1) Metals are malleable, therefore, they can be engraved with currency symbols and political leaders.
2) Metals are shiny in color and make more attractive coins!
3) Metals aren't easily shattered or broken, for they aren't brittle like nonmetals.

Extra Credit Report (3)

The Unkindest Cut:


Paper cuts are thought to be  one of the most agonizing injuries. Medical journals believe that these cuts have a high possibility of infection. The irony of paper cuts is that they tend to occur with the highest quality of paper. This paper of high quality has enough stiffness to cut like a razor's edge. Your fingertips are loaded with nerve ending, including pain-interpreting nociceptors, which are necessary for the constant exploration of the environment. Money is softer than paper, which is why it is uncommon for one to get a paper cut on bills. Even more than money though, newspapers are the least likely to inflict a paper cut. 

Riverwood Fish Kill: What Killed the Fish?

As we went through the data, the only spike was for rainfall in August. Once that data was compared to different chemicals, we found an abnormal amount of pesticide. We concluded that after the pesticides were sprayed across crops, there was a heavy rainfall that washed into the nearest river, killing the fish in Riverwood. This caused the Riverwood fish kill. 

Homework #13

20.

a. a tomato.

b. pure water.

c. milk of magnesia.

21. Because on the pH scale there is a ten increment difference, a solution at pH 4.0 is 100x more acidic than a solution at pH 2.0.

22.

Too low pH:

1) Fish egg development impaired, which harms the process of reproduction. 

2) Increased concentrations of metal ions in natural waters by leaching metal ions from surrounding soil.

High pH:

3.Scales on fish dissolve organic materials.

23. Polar molecules are molecules whose ends have opposite and asymmetrical charges. Polar molecules because “the opposites attract” cause the molecules to attract. Non-polar molecules have the same charge ends which make the ends repel one another.

24. Because water and ethanol are polar substances, you would choose the lamp oil to dissolve the nonpolar molecular substance.

25. Salt dissolves in water because it homogeneously mix throughout the solution. Salt cannot dissolve in cooking oil because it creates a suspension, and the salt particles cannot be fully mixed throughout.

26. This relationship between solvents that dissolve solutes with similar electrical charges is described as "like dissolves like."

27. Water would not be able to dissolve the grease on dishes because oil is composed of nonpolar molecules. The dishes to remove the grease would have to be washed with a solution composed of non-polar molecules.

33.

a. Nonpolar materials are likely to be found in these cleaners.

b. Using these cleaners would be more effective than washing with water because since water molecules are polar, they would not dissolve the grease off of the mechanics' hands. Instead, the water would sort of roll off of their hands without them being cleaned.

35. Fluorine has the highest electronegativity of any element, so it would make a negative end of the polar bond. Hydrogen has less negative charges than fluorine, so it would have a partial positive charge of the polar bond.

Homework #12

ISBS #9-19 pg. 81-82:


9. 

.20 x 55 = 11

11g sugar.

55-11 = 44

44g water.

11g sugar, 44g water. 

10. 15,000ppm

11. When the oxygen atom is negatively charged and the hydrogen atoms are positively charged, a water molecule is polar. 

12. See drawing 

13. 

a. The negatively charged end, the oxygen end.

b. The positively charged end, the hydrogen end.

14. Because heavy metals carry atoms that have greater masses than essential metallic elements. 

15. Numbness, staggered walk, tunnel vision.

16. 

1) Soil surrounding heavily traveled roads, for it may have absorbed automobile exhaust from the gas from cars that contained tetraethyl lead before the 1970s.

2) Flaking leaded paint in houses built before 1978/.

b.

1) Thermometers and florescent light bulbs.

2) Fish exposed to mercury in the water. 

17. Hydroxide (OH-) is found in many bases.

18. Hydrogen.

19. 

a. basic.

b. basic.

c. acidic.

d. chemically neutral.