1. The nucleus of the atom contains ______________ and _______________.

2. The _____________ are found outside the nucleus of the atom.

3. The atom is _______________ (no overall charge) because the number of positive charges balances the number of negative charges.

4. The electron is _______________ charged. The symbol for an electron is ________.

5. The proton is _______________ charged. The symbol for a proton is ________.

6.The neutron is _______________ charged. The symbol for a neutron is ________.

7.The atomic number of an element represents the number of _______________ in the atom. The symbol for the atomic number is ________.

8.In an atom, the number of ____________ equals the number of _____________. Therefore, the atomic number “Z” also tells the number of _____________ in an atom.

One of the squares on the periodic table usually looks much like this:

6	Atomic number (Z)
C	Symbol
12.011	Average atomic mass

Always look at the Legend on each periodic table to be sure of the information given in the square.

9.The atomic mass number of an element represents the sum of the number of _____________ and the number of ________________ in the nucleus. The symbol for mass number is “A”.

10.Since almost all of the mass in an atom comes from the nucleus, you can determine “A” from the periodic table, simply rounding the ___________________ to the nearest whole number.

A=#p⁺+#n^o

So…#n^o=A-Z

A=Z+#n^o

11.Determine the Z’s and A’s for each of the following elements by looking on a periodic table.

Chlorine

Magnesium

Copper

Silver

Silicon

Xenon

A =

Z =

Element notation is a symbolic way to write an element’s A and Z with the symbol:

The element notation for sulfur looks like this:

The A is to the top left, and the Z is to the bottom left

The names of isotopes are written with the A following the name.

Complete the following table:

62.Find the density of a wood block that has a volume of 5.0 cm³ and a mass of 0.5 g.

63.What volume would a rock occupy if it had a mass 31.2 g and a density of 10.4 g/cm³?

64.Calculate the mass of a wood block that is 4.0 cm long, 2.0 cm wide, 6.0 cm high, and has a density of 0.50 g/cm³.

65.Which has the greater mass. 10 cm³ of steel (D = 1.8 g/cm³) or 5 cm³ of mercury (D = 13.6 g/cm³)?

66.Suppose you mix: 0.4 liter of red tinted oil (D = 0.90 g/mL) with 0.4 liter of blue tinted seawater(D = 1.025 g/mL) in a one liter container. After sealing the container, you shake the mixture and come back in 1 hour. What do you see in the container?

67.You have a substance shaped in a cube with a side length = 2.0 cm. The cube's mass is 24 g. What is the density of this substance?

68.Another cube of the same substance as the cube in the previous question has a side length = 4.0 cm. What is the density of this cube?

69.A jeweler suspects that a piece of gold jewelry in his collection is a fake. He knows that the density of gold is 19.3 g/cm³. If the volume of the piece of jewelry is 6.00 cm, and its mass is 109 grams, is the piece a fake? Why or why not?

70.A 500.0 mL graduated cylinder filled with milk has a mass of 620.0 grams. The mass of the container is 35 grams. What is the density of the milk?

71.Substances A and B have the same volume, but the mass of B is twice as great as the mass of A. How do the densities of the two substances compare?

72.An irregular-shaped object has a density of 8.0 g/cm³. Its mass is 72 grams. How many cubic centimeters of water will it displace?

73.A cube of cork has a density of 0.24 g/cm³. It floats in water. Suppose you cut a hole in the cork and place lead (D = 11.3 g/cm³) inside. Now it sinks in water. Why does it sink? Have your changed the density of the substance cork? What have you changed?

74.How large a container would you need to hold 195 grams of a liquid that has a density of1.3 g/cm³?

75.The density of gasoline is 0.70 g/cm³. Would you use water to put out a gasoline fire? Why

Solubility and Acids & Bases

76.How does a solute differ from a solvent?

77.Give two examples of each a (solute and a solvent).

78.Describe how table salt dissolves in H₂O.

79.What factors determine the rate at which a solute dissolves?

80.Briefly explain how each factor above effects the rate of dissolving for a solute in a liquid solvent.

81.How do temperature and pressure effect the solubility of a gas in a liquid?

82.Distinguish between an unsaturated and a saturated solution.

83.What is a supersaturated solution?

84.Identify the solute and the solvent in each of the following. a). ocean water, b). carbonated water, c) a beaker full of colored water, d). a sugar water solution

85.How can you determine whether a solution is saturated, unsaturated, or supersaturated?

Solubility in g/100 g of Water at the Temperature Indicated

Compound	0°C	20°C	60°C	100°C
NH₄Cl	29.4	37.2	55.3	77.3
PbCl₂	0.67	1.00	1.94	3.20
KBr	53.6	65.3	85.5	104
NaClO₃	79.6	95.9	137	204

86.Use the data table above to determine whether the solutions below are saturated, unsaturated, or supersaturated.

a. 45.6 g of NH₄Cl dissolved in 100g water at 20°C.

b. 0.70 g of PbCl₂ dissolved in 100g water at 20°C.

c. 65.3 g of KBr dissolved in 100g water at 20°C.

d. 90.5 g of NaClO₃ dissolved in 100g water at 20°C.

87.Give a definition and an example of an acid.

88.Give a definition and an example of a base.

89.Describe what happens in a neutralization reaction?

90.What does the pH scale measure?

91.Given the following pH values classify each substance. a). shampoo 5.8, b). blood 7.2, c). ammonia 11.5, d). vinegar 3.0, e). pure water 7.0, f). milk of magnesia 10.5

92.From the list in #91, identify which substance is the most basic and which is the most acidic.

93.From the list below determine whether the description or property refers to an acid, a base, or both an acid and a base. Use the following key: A= Acid B= Base AB= Acid and Base.

Solubility and Acids & Bases

Solubility in g/100 g of Water at the Temperature Indicated

Solubility Curve