2SAS #26-34, p. 132 and 2SBS #1-8, p.151

2SAS:

26) Which are more likely to lose electrons, metallic elements or nonmetallic elements?

Metallic elements form cations; therefore, metallic elements are more likely to lose electrons.

27) Noble gas elements rarely lose or gain electrons. What does this indicate about their chemical reactivity?

Noble gas elements are unreactive and chemically inert.

28) Predict whether each of the following elements would be more likely to form an anion or a cation: (Note: Anions are negatively charged; cations are positively charged.)
a. Na
b. Ca
c. F
d. Cu
e. O
f. Li
g. Sn
h. I

a. cation.
b. cation.
c. anion.
d. cation.
e. anion.
f. cation
g. cation.
h. anion.

29) Which pair is more similar chemically? Defend your choice:
a. copper metal and copper (II) ions
or
b. oxygen with mass number 16 and oxygen with mass number 18

a. copper metal and copper (II) ions: copper metals form cations, and the only difference between copper metal and copper (II) ions is the absence of 2 electrons. Oxygen with mass number 18 as opposed to 16 exhibits an isotope. Neutrons are way bigger than electrons which equal 1/2000 neutrons, so a change in neutrons is a bigger change.

30) The diameter of a magnesium ion (mg^2+) is 156 pm (picometers, where 1 pm = 10^-12 m); the diameter of a strontium ion (Sr^2+) is 254 pm. Estimate the diameter of a calcium ion (Ca^2+).

156+254=410
410/2=205; 205 pm.
The diameter of a calcium ion (Ca^2+) = 205 pm.

31) Three kinds of observations that may indicate a chemical change appear in the following list. However, a physical change may also result in each observation. Describe a possible chemical cause and a possible physical cause for each observation:
a. change in color.
b. change in temperature.
c. formation of a gas.

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) Identify the element that is described by each of the following statements:
a. This element is a nonmetal. It forms anions with a 1- charge. It is in the same period as the metals used in a penny.
b. This element is a metalloid. It is in the same period as the elements found in table salt.

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

33) Compare your use of the Snake River data to solve the fish-kill mystery in Unit 1 to Mendeleev's use of element data to create the periodic table.

Mendeleev used atomic weight along with similarities in chemical and physical properties to organize the periodic table. 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) Mendeleev arranged elements in his periodic table in order of their atomic weights. In the modern periodic table, however, elements are arranged in order of their atomic numbers. Cite two examples from the periodic table for which these two schemes would produce a different ordering of adjacent elements.

Argon (atomic weight: 39.95) would have had to be placed after potassium (atomic weight: 39.10), and cobalt (atomic weight: 58.93) would have had to be placed after nickel (58.69) in order to be accurate in Mendeleev's original periodic table.

2SBS:

1) List two resources typically found in each of the three major "spheres" of Earth.

Atmosphere: nitrogen, oxygen, neon, and argon.
Hydrosphere: water and dissolved minerals.
Lithosphere: petroleum and metal-bearing ores.

2)
a. List and briefly describe three major parts of the lithosphere.
b. Which layer serves as the main storehouse of chemical resources used in manufacturing consumer products?

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) Identify the nation that produces the most
a. silver.
b. copper.
c. tin.

a. Mexico.
b. Japan.
c. China.

4) According to the information in Table 2.3 on page 136, which of these four nations-- the US, Australia, China, or Brazil-- produces the largest masses of the eight listed resources in the table?

China produces the largest masses of the eight listed resources in the table.

5) How do minerals differ from ores?

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) What factors determine the feasibility of mining a particular metallic ore at a certain cite?

-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) A nineteenth-century gold mine, inactive for over 100 years, has recently reopened for further mining. What factors may have influenced the decision to reopen the mine?

Maybe the gold had replenished after 100 years and demand for gold was high.

8) What is meant by referring to the quantity of "useful ore" at a sight.

Useful ore refers to the amount, usually as a percent, of the desired mineral being mined.