Review 1 Ch 2 & 3

1) carbon, hydrogen, nitrogen, oxygen

2) atomic number.

3) protons and neutrons

4) 31 daltons

5) 20 protons. 20 electrons.

6) 19 daltons

7) isotopes

8) number of neutrons

9) 2 more neutrons than carbon-12.

10) two more neutrons than hydrogen-1.

12) an electron may move to an electron shell farther out from the nucleus.

13) has 8 electrons in its outer electron shell. And is inert.

14) electrons in the outer valence shell in the atom.

15) be stable and chemically nonreactive or inert.

16) 2

17) 1

18) outer-shell electrons of two atoms are shared so as to satisfactorily fill the outer electron shells of both atoms.

19) molecules

20) 2

21) 4

22) Each hydrogen atom has a partial positive charge.

23) nonpolar covalent bonds.

24)

a polar covalent bond

25) one of the atoms sharing electrons is more electronegative than the other atom.

26) H₂O

27) chlorine gains an electron from sodium.

28) Covalent bonds involve the sharing of electrons between atoms and ionic bonds involve the electrical attraction between atoms

29)ionic bond

30 an ionic bond

31)hydrogen bond

32) electrons are not symmetrically distributed in a molecule.

33) The weak attraction between the nucleus of one molecule and the electrons of a nearby molecule.

34) polar covalent bonds.

35) a hydrogen bond

36) hydrogen bonds

37) All are properties related to hydrogen bonding.

38) A water strider can walk across the surface of a small pond.

39) the amount of heat required to raise the temperature of 1 kg of water by 1°C

40) absorption and release of heat when hydrogen bonds break and form.

41) hydrogen bonds

42) high heat of vaporization of water.

43) the formation of hydrogen bonds releases heat.

44) the release of heat by the formation of hydrogen bonds

45) 4°C

46) hydrogen

47) Hydrogen bonds stabilize and keep the molecules of ice farther apart than the water molecules of liquid water.

48) nonpolar substances that repel water molecules.

49) Dissolve 90 g of glucose in a small volume of water, and then add more water until the total volume of the solution is 1 L.

Figure 3.2

50) 60

51) 30

52) 150

53) neutral

54) pH 2

55)

pH 8

56) gastric juice at pH 2

57) seawater at pH 8

58) concentration of H⁺ has increased 10 times what it was at pH 9. And concentration of OH^- has decreased 10 times what it was at pH 9.

59) concentration of OH^- is 100 times greater than what it was at pH 5.

60) 10,000 times more

61) 100,000 times more

62) the HCO₃^- to act as a base and remove excess H⁺ with the formation of H₂CO₃.

63) hydrogen bonds.

64) cohesion

65) when a water molecule gains an hydrogen ion from another water molecule

66) hydrogen ions is equal to the concentration of hydroxide ions.

67) the absorption of heat by the breaking of hydrogen bonds

68) the body of higher temperature to the one of lower temperature.

69) bonds between water molecules.

70) wax

71) 60.0 g