Study guide - Chapter 02

For how long did life evolve in water before spreading onto land?
What is the most important substance required by living organisms?
What is matter?
What is an element? How many elements are found in nature?
What is a compound? Name an example.
Name the four most abundant elements in most living organisms. What other elements are
essential for living organisms?
7. What are trace elements? Name examples and their particular function.
8. Name the three subatomic particles studied in class. What are their characteristics? How are
these subatomic particles distributed in an atom? What holds them “in place”?
9. What is the atomic number of an atom? What is the mass number? What is the atomic mass?
10. What is an isotope? Do isotopes of the same element behave different in chemical reactions?
11. What is a radioactive isotope? How are these dangerous to living organisms? How are they
12. What is an electron shell? What determines the number of electron shells present in an atom?
13. What is a valence shell? What does the number of electrons in the valence shell determines?
14. How do atoms react with each other?
15. What is a chemical bond? What are the three types of chemical bonds studied in class?
16. Describe a covalent bond?
17. What is a molecule?
18. Name and briefly describe the three different ways of representing molecules.
19. Define electronegativity of an atom.
20. What is the difference between a nonpolar and a polar covalent bond?
21. Describe how the electronegativity of oxygen affects the water molecule.
22. What is an ion?
23. Describe an ionic bond?
24. Describe a hydrogen bond.
25. What is a chemical reaction? In a chemical reaction, what do we call the starting materials?
What do we call the resulting materials?
26. What happens to the atoms of molecules in a chemical reaction?
27. Describe cohesion.
28. Describe adhesion.
29. Describe surface tension.
30. What is heat? How is it temperature related to heat?
31. How is heat exchanged when hydrogen bonds form or break?
32. Describe the heat storage capacity of water.
33. Describe evaporative cooling.
34. Describe how water is less dense as a solid than a liquid. Why is this important for life on Earth?
35. What is a solution? Define solvent and solute. What is an aqueous solution?
36. What characteristic of water makes it such a “good” solvent?
37. Why is water called the solvent of life?
38. What happens to water molecules in a water solution?
39. What is an acid? What is a base?
40. How does the concentration of hydrogen ions change in the pH scale?
41. How do we define a neutral solution?
42. What is a buffer? Why is it important for humans to have natural buffers in our blood?
43. What is ocean acidification? How does it affect coral reefs?
44. What is acid precipitation? What causes acid precipitation?