Name: ______
Date: ______Hour: ____
Chapter 4 Online Questions
Activity 4.1
1. Which of the substances named above are compounds rather than elements? Explain.
2. When oxygen gas and hydrogen gas combine, they form water. What does this indicate about the properties of new compounds that are formed from different elements?
Activity 4.2
1. How many electrons are in the highest occupied energy level of a nitrogen atom? ______
2. The atomic number of an uncharged atom of phosphorus is 15. How many protons would you expect it to have? How many electrons?______, ______
3. Is it possible to predict the number of neutrons in the atomic nucleus of phosphorus? Explain.
Page 2
1. What is the difference between the atomic structure of Carbon–12 and Carbon–14?
2. The atomic number of calcium is 20. How many electrons would you expect it to have?______
Activity 4.3
1. How many single bonds are there in a methane molecule?______
2. In a water molecule, H2O, how many electrons does oxygen share with each hydrogen atom?
3. Lithium has an atomic number of 3. How many electrons are in its highest occupied energy level? Fluorine has an atomic number of 9. How many electrons are in its highest occupied energy level? ______, ______
4. Lithium forms an ionic bond with fluorine. During this process, which one of the atoms becomes a positively charged ion? Explain your answer.
Page 2
1. How many single bonds are in CO2? How many double bonds?
2. How did you distinguish between covalent bonds and ionic bonds in this activity? Explain.
(Skip page 3)
Activity 4.4
1. Describe how two water molecules can be compared to two magnets.
Page #2
1. Look at the animation of the water strider and the water molecules at the surface of the pond. What keeps the water strider from sinking?
2. How do the water molecules reach the top of the cattail?
3. Why is water a good solvent for ions, such as K+ and Na+?
4. Why does ice float on the surface of the pond in winter?
Page #3
1. When the numbers of OH– and H+ ions are the same, the solution is said to be neutral and has a pH of ______
2. What happened to the pH reading when the acid was added to the water? What happened to the pH reading when the base was added to the water?
3. Suppose you found the pH of orange juice to be 4.20, and the pH of lemon juice to be 3.50. Which of the two juices is more acidic?______
4. Pure water is composed of particles including H2O molecules, hydrogen ions (H+), and hydroxyl ions (OH–). At a pH = 7.0, which of these three is most abundant?
Page #4:
1. What happened when you added acid to the water? Base to the water?
2. What happened when you added acid to the liver? Base to the liver?
3. Can you suggest a reason that the liver solution behaved differently from the water solution after the addition of acid and base?
4. Death may occur if the pH of human blood goes above 7.55 or below 7.35. How can the pH of blood be maintained within these narrow limits?