Answer the following question given this paragraph: osmol = M i If more than one solute is present in a solution, the individual osmolarities are additive to get the total osmolarity of the solution. Solutions that have the same osmolarity have the same osmotic pressure. If solutions of differing osmolarities are present on opposite sides of a semipermeable membrane, solvent will transfer from the lower-osmolarity solution to the higher-osmolarity solution. Counterpressure exerted on the highosmolarity solution will reduce or halt the solvent transfer. An even higher pressure can be exerted to force solvent from the high-osmolarity solution to the low-osmolarity solution, a process called reverse osmosis. Reverse osmosis is used to make potable water from saltwater where sources of fresh water are scarce. Q: If solutions of differing osmolarities are present on opposite sides of a semipermeable membrane, solvent will transfer from what to what, in terms of osmolarity of the solution? Choices: - low to low - high to high - high to low - low to high A:
low to high
(Question)
Answer the following question given this paragraph: polar, while others are strongly polar. Ionic bonds can be considered the ultimate in polarity, with electrons being transferred rather than shared. To judge the relative polarity of a covalent bond, chemists use electronegativity, which is a relative measure of how strongly an atom attracts electrons when it forms a covalent bond. There are various numerical scales for rating electronegativity. Figure 4.4 "Electronegativities of Various Elements" shows one of the most popularthe Pauling scale. The polarity of a covalent bond can be judged by determining the difference in the electronegativities of the two atoms making the bond. The greater the difference in electronegativities, the greater the imbalance of electron sharing in the bond. Although there are no hard and fast rules, the general rule is if the difference in electronegativities is less than about 0.4, the bond is considered nonpolar; if the difference is greater than 0.4, the bond is considered polar. If the difference in electronegativities is large enough (generally greater than about 1.8), the resulting compound is considered ionic rather than covalent. An electronegativity difference of zero, of course, indicates a nonpolar covalent bond. Q: What kind of bonds, where electrons are transferred rather than shared, are considered the ultimate in polarity? Choices: - covalent bonds - soluble bonds - magnetic bonds - ionic bonds A:
(Answer)
ionic bonds
Ques: Answer the following question given this paragraph: With logistic growth, the population starts out growing slowly, and then the rate of growth increasesbut only to a point. The rate of growth tapers off as the population size approaches its carrying capacity. Carrying capacity is the largest population size that can be supported in an area without harming the environment. This type of growth characterizes many populations. Q: With logistic growth, how does population growth start out? Choices: - exponentially - rapidly - steadily - slowly A:
Ans: slowly
(Q).
Answer the following question given this paragraph: Give an example of how matter cycles. While matter cycles round and round in the Earth System, ENERGY FLOWS through the Earth System. The vast majority of Earth's energy comes from the sun, flows into the Earth's System, and flows out of the Earth's System into space. If all the energy that comes to Earth from the sun were to stay on Earth, the Earth would melt away. But the energy that comes to Earth from the sun does not stay. Eventually it radiates back out to space as heat. We know this because the average temperature of the Earth has remained relatively constant. If the energy from the sun were to stay on Earth, the Earth's average temperature would rise. Some of the sun's energy is reflected by the atmosphere, some is absorbed by the Earth and re-radiated as heat, some evaporates water and powers the water cycle, some is captured by plants and used to make sugars, and some powers the wind but eventually ALL of the energy that comes to the Earth from the sun leaves the Earth and flows into space. For this reason we say that energy flows through the Earth System. Q: Where does most of the earth's energy come from? Choices: - magnetic field - its core - its atmosphere - sun A:
(A).
sun
Ques:Answer the following question given this paragraph: Do you like toast? Did you ever look inside a toaster while it's toasting bread? When you push down the lever to turn on the toaster, the metal heating element inside starts to glow orange or red almost instantly. You can see the glowing heating element inside this yellow toaster. The glowing metal shows that the heating element has become very hot. It gets hot so quickly because metals are good conductors of thermal energy. Q: Why does the heating element of a toaster get hot so quickly? Choices: - charged battery - magnetic force - good insulator - good conductor A:

Ans:good conductor
Answer the following question given this paragraph: Biological sources of air pollution include molds, pollen, and pet dander. Q: Molds, pollen, and pet dander are examples of air pollution with what type of source? Choices: - ecological - physical - chemical - biological A:
biological