in a collection of four marbles, 25% of the marbles have a mass of 5.00 g and 75% of the marbles have a mass of

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26.00 g

5.00 g

7.00 g

The average mass of a marble can be determined by dividing the total mass of the marbles by the total

number of marbles:

1x5.00 g +3x7.00 g

4

(Method 1)

Or, the average mass of a marble in this collection can be determined by (a) multiplying the fraction of

marbles of a particular type by the mass of a marble of that type and (b) taking a sum over all types of

marbles:

= 6.50 g

0.2500 x 5.00 g +0.7500 x 7.00 g = 6.50 g

(Method 2)

1. How many of the four marbles in Model 3 have the same mass as the average mass? none

2. For a large number of marbles (assume that the actual number of marbles is unknown), 37.2 % have a mass

of 10.0 g and 62.8 % have a mass of 12.00 g. Which of the two methods in Model 2 should be used to

determine the average mass of this collection? Send method

Explain your answer.

The second method because it helps find the average

fraction of marbles + mass.

mass

3. Using the method indicated in #12 and the data in Table 1,

bns ni awans buy no b9258

a. Calculate the average mass of a chlorine atom in amu. (This represents the average mass of a chlorine

atom if you had a lot of them!) 0.16.35 +0.24.37= 35.48 ama

35, 44 ами

7600

b. What fraction or percentage of chlorine atoms has this average mass?

c. What is the average mass of a chlorine atom in grams? (1 amu= 1.6606 x 1024 g)

35.48

d. Calculate the mass (in grams) of 6.022 x 1023 (randomly selected) chlorine atoms.

35.39-1.66 1024 = 5.10-23

-23

as a

5.90

e. Examine the periodic table and find the symbol for chlorine. How does the number given just below the

symbol for chlorine (rounded to 0.01) compare with the average mass (in amu) of one chlorine atom?

The number