2. When trying to identify an unknown element, a scientist determines what other elements the unknown element reacts with chemically. Which property of the unknown element determines the other elements it reacts with? The total number of particles in the nucleus of the unknown element The number of valence electrons in the unknown element The total number of neutrons in the unknown element The number of protons in the nucleus of the unknown element o o o o

You are stranded on a lifeboat with several other people in the middle of the ocean.  You have run out of clean drinking water and are very thirsty.  The others have started to drink the seawater to quench their thirst. Since you’re waiting for rescue (and are a top notch AP Biology student), you decide to solve a couple of water potential problems to determine if drinking sea water is a good idea or not.  a) The majority of dissolved ions in seawater is NaCl, roughly a 0.5M concentration.  The ionization constant of NaCl is 2.0.  Calculate the solute potential for seawater if you know that the water is 2°C. b) Your own cells have a 0.15M concentration.  Calculate the solute potential for your own cells, knowing that body temperature is 37°C. c) Using your knowledge about water potential, if you drink the seawater, wat will happen when the seawater comes into contact with your body’s cells? Note: ΨP for animal cells is zero

1. A peer-reviewed scientific journal articles. is usually based on either past experiences or information gained from reading 2. variables are kept the same to maintain consistent testing conditions across all experimental samples. 3. provides a quick, albeit inaccurate, means of obtaining the pH of a solution. 4. Substances whose pH values are above 7.00 are considered ; substances whose pH values are below 7.00 are considered 5. During a reaction, molecule B receives an electron(s) from molecule A, leaving molecule A oxidized. 6. The reagent is used to detect the presence of complex sugars (ex. starch) in solutions. 7. Reducing sugars, such as glucose, will always react with Benedict's reagent because these sugars have a(n) functional group. 8. are molecules which donate protons (H+) in solution very easily.

The protons and neutrons are contained within the of the atom. O Electron Cloud Atomic Center Middle O Nucleus

Element Atomic Number Mass Number Number of Protons Number of Neutrons Number of Electrons Carbon-12   12 6     Nitrogen-14       7 7 Chlorine-35   35 17     Oxygen-16         8 Carbon-14

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The biggest difference between elements and molecules is that elements only have one TYPE of atom, while molecules have MULTIPLE types of atoms. O True False

12. What is the pH of a solution in which [OH] = 0.000005 M? )5.3 8.7 O 5 x10