Jeopardy Atoms Bonds Solutions pH Water Q $100 Q $100 Q $100 Q $100

What is the charge on a proton? $100 Question: Atoms What is the charge on a proton? A neutron? An electron?

$100 Answer: Atoms Protons are positively charged. Neutrons are neutrally charged. Electrons are negatively charged.

$200 Question: Atoms How do you find the number of neutrons in the nucleus of an atom?

$200 Answer: Atoms Subtract the atomic number from the atomic mass.

$300 Question: Atoms Explain why an atom has the same number of protons and electrons when it’s neutrally charged.

$300 Answer: Atoms Protons are positively charged. Electrons Are negatively charged. When you have Same number of protons and electrons, The charges balance and the atom is neutral.

$400 Question: Atoms Draw Bohr diagrams for three of the elements key to life.

$400 Answer: Atoms Results will vary.

$500 Question: Atoms A student draws a model of an atom’s nucleus with all the protons clustered together and all the neutrons clustered together. What’s wrong with her picture?

$500 Answer: Atoms Protons are positively charged and will repel each other. Interspersing neutrons (rather than clustering them together) minimizes that effect. This is particularly true in larger atoms!

$100 Question: Bonds What is an ionic bond? What charge does each atom in an ionic bond take on?

$100 Answer: Bonds An ionic bond is a bond between a metal and a nonmetal in which the metal donates an electron to a nonmetal. The metal becomes positively charged and the nonmetal becomes negatively charged.

$200 Question: Bonds What is the difference between an intermolecular bond and an intramolecular bond? Give an example of each.

$200 Answer: Bonds Intramolecular bonds are within one molecule. Intermolecular bonds are between two or more molecules. Ionic and covalent bonds are intramolecular. Hydrogen bonds are intermolecular.

$300 Question: Bonds Compare and contrast covalent and hydrogen bonds.

$300 Answer: Bonds Covalent bonds are between two nonmetals. They are intramolecular bonds that involve the sharing of electrons equally (nonpolar covalent bonds) or equally (polar covalent bonds). Hydrogen bonds form between two or more polar covalent molecules. They are intermolecular bonds that involve a weak attraction between a slightly positive end of one molecule and a slightly negative end of another.

$400 Question: Bonds Draw EITHER the formation of an ionic bond between sodium and chlorine or a covalent bond between one oxygen and two hydrogen atoms.

$400 Answer: Bonds Return.

$500 Question: Bonds Why can’t nonpolar covalently bonded molecules form hydrogen bonds? Your answer should be at least 4 sentences.

$500 Answer: Bonds In nonpolar covalent bonds, there is a relatively equal distribution of electrons among the atoms. Therefore, the molecule is evenly charged. Because of the equality in charge, atoms do not attract or repel one another. Because of this they cannot form hydrogen bonds.

$100 Question: Solutions Define solution.

$100 Answer: Solutions A substance into which a solute is dissolved into a solvent and in which the solute is distributed evenly.

$200 Question: Solutions Soda is a solution. What is the solute? What is the solvent?

$200 Answer: Solutions Solute: Sugar, CO2, salt, flavoring Solvent: Water

$300 Question: Solutions Describe how to perform a serial dilution. How are serial dilutions used in experiment?

$300 Answer: Solutions Diffusion Serial dilutions - made by taking 1 pt stock solution and diluting w/ 9pts H2O, then diluting the resulting solution similarly. Serial dilutions are used in experiments when we want to dilute chemicals, etc., in a regulated way.

$400 Question: Solutions You are designing an experiment to test how much nicotine (a toxic substance in cigarettes) a certain organism can tolerate. you want to test various concentrations of nicotine. Explain how you would incorporate serial dilutions into the lab.

$400 Answer: Solutions You can extract nicotine from cigarettes. This extract becomes your stock solution. You can then use a serial dilution to test the organism at various concentrations.

$500 Question: Solutions You want to grow bacteria on a petri dish (a plate used for cell cultures). However, every time you put bacteria on the plate, too many grow to count. How could you get fewer bacteria onto the plate? What you have What you want

$500 Answer: Solutions Use a serial dilution! You begin with a stock solution of bacteria, then dilute it to suit your needs.

$100 Question: pH Define “acid” and “base.” Give an example of each.

$100 Answer: pH Acid - a substance with a pH from 0-6.9999 where the number of H+ ions is greater than the number of -OH ions. Ex. Vinegar Base - a substance with a pH frome 7.0001- 14 where the number of -OH ions is greater than the number of H+ ions Ex. Baking soda.

$200 Question: pH What color does a pH indicator usually turn an acid? What color does it usually turn a base? A neutral?

$200 Answer: pH Acid - red; base - blue-green; Neutral - purple/clear

$300 Question: pH Compare and contrast qualitative and quantitative data. Give an example of each.

Qualitative data is data that uses observation and generally $300 Answer: pH Qualitative data is data that uses observation and generally doesn’t use numbers. Ex. Color, smell, etc. Quantitative data is data that uses Numbers and precise measurements. Ex. Length, mass, volume, etc.

$400 Question: pH You are given an unknown solution and asked to determine its pH. Describe how you would determine its pH. What would you compare it to? What qualitative and quantitative data would you collect?

$400 Answer: pH Test the solution using a pH indicator Evaluate its color (qualitative). Determine if the solution is an acid, base or neutral. 4) Assign it a pH value - a quantitative value.

$500 Question: pH You are given an unknown solution and asked to determine its pH, but you’re out of pH indicator. However, you do have a way of testing how many and what kinds of ions are in the solution. From this information, how could you determine the pH?

$500 Answer: pH Rather than testing for pH directly, you can test for the concentration of H+ and -OH ions. Substances with a greater concentration of H+ ions than -OH ions are acids. Substances with a greater concentration of -OH ions than H+ ions are bases. Substances with equal concentrations are neutral.

$100 Question: Water Define adhesion. Define cohesion.

$100 Answer: Water Adhesion is the tendency of water to stick to things. Cohesion is the tendency of water to stick to itself.

$200 Question: Water Compare and contrast two of the properties of water.

$200 Answer: Water Adhesion vs. Cohesion Surface Tension vs. Capillary Action Density vs. temperature change Solvent vs. ionization

$300 Question: Water A basilisk is a lizard that can run on the surface Of water. (Video shown below.) What property Of water is likely involved in this ability? Justify your answer in at least 2 sentences. http://video.aol.com/video-detail/jesus-christ-lizard/2936479452

$300 Answer: Water The lizard is likely using the surface tension of the water. Water has a high surface tension due to its ability to form hydrogen bonds between molecules.

$400 Question: Water Explain how hydrogen bonds contribute to The properties of water. Your answer should Include an illustration of hydrogen bonds and an explaination of AT LEAST two properties of water.

$400 Answer: Water Because water is a polar covalent molecule, It has an uneven distribution of electrons. Therefore, it can form hydrogen bonds between its molecules. These hydrogen bonds cause water to stick to itself and other polar molecules. It also causes water to form surfaces and climb tubes. Lastly, it arranges into crystals, forming ice, which has a lower density than liquid water. H H Oxygen Oxygen H H

$500 Question: Water Water’s special properties are based on its ability to form hydrogen bonds between polar molecules. Predict what will happen when a substance with both polar and nonpolar ends (shown below) is added to water. Polar Nonpolar

$500 Answer: Water Putting a substance that’s both polar and nonpolar into water interupts the hydrogen bonds between water molecules. Dish soap is polar and nonpolar - that’s why it didn’t climb up the paper towel through capillary action.

Final Jeopardy A gelatin block is prepared with some dyed solution added to it. The dye will be clear in the presence of acid, but turn pink near a base. The block is placed in a plastic bag. The block is placed above a container that contains ammonia. After 1/2 an hour, the block turns pink. Why does the gelatin undergo a color change?

Final Jeopardy Answer Ammonia, a base, moved through the plastic bag (a membrane) by diffusion. The membrane is selectively permeable because it let the ammonia in, but didn’t let the gelatin out.