Chapter 2 Quiz Review of attempt 1 Fi nish r eview Started on Wednesday, 25 January 2012, 12:26 PM Completed on Wednesday, 25 January 2012, 12:43 PM Time taken 17 mins 2 secs Marks 7/11 Grade 6 out of a maximum of 10 ( 64%) Question1Marks: 1 A hypothetical element is composed of three isotopes with the following masses and abundances: 48.01 X (23.5%; 48.01 amu), 34.97 X (45.500%; 34.97 amu), 42.28 X (31.000%; 42.28 amu). Calculate the average atomic mass of this element? Even though it is incorrect to do so, enter your answer to 3 decimal places in order to humor the computer. Answer: 125.260 Convert percentage to decimal for each isotope.Multiply respective decimal by the massAdd all these numbers together. Although this is an "average" you do NOT divide by the number of components Incorrect Marks for this submission: 0/1. Question2Marks: 1 How many neutrons are contained in the nucleus of a 75 Se atom. Choose one answer. a. 75 b. 34
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Finish review Started on Wednesday, 25 January 2012, 12:26 PM
Completed on Wednesday, 25 January 2012, 12:43 PM
Time taken 17 mins 2 secs
Marks 7/11
Grade 6 out of a maximum of 10 (64%)
Question1 Marks: 1
A hypothetical element is composed of three isotopes with the following masses andabundances: 48.01X (23.5%; 48.01 amu),34.97X (45.500%; 34.97 amu), 42.28X (31.000%;42.28 amu). Calculate the average atomic mass of this element? Even though it isincorrect to do so, enter your answer to 3 decimal places in order to humor thecomputer.
Answer:125.260
Convert percentage to decimal for each isotope.Multiply respective decimal by themassAdd all these numbers together.Although this is an "average" you do NOTdivide by the number of components IncorrectMarks for this submission: 0/1.
Question2 Marks: 1
How many neutrons are contained in the nucleus of a 75Se atom.
A fishing boat accidentally spills 9.0 barrels of diesel oil into the ocean. Each barrelcontains 42 gallons. If the oil film on the ocean is 2.5 x 10 2 nm thick, how many squaremeters will the oil slick cover? Assume that the oil slick forms a cube rather than acylinder.
Choose one answer.
a. 5.7 x10-3 m2
b. 5.7 x106 m2
c. 5.7 x107 m2
d. noneof these
CorrectMarks for this submission: 1/1.
Question11 Marks: 1
Because of the high heat and low humidity in the summer in Death Valley, California, avisitor requires about one quart of water for every two miles traveled on foot. Calculate
the approximate number of liters required for a person to walk 20. kilometers in DeathValley.
A hypothetical element is composed of three isotopes with the following masses andabundances: 114.91X (50.0%; 114.91 amu),124.55X (45.500%; 124.55 amu), 117.96X(4.5000%; 117.96 amu). Calculate the average atomic mass of this element. Eventhough it is incorrect to do so, enter your answer to 3 decimal places in order to humorthe computer.
Convert percentage to decimal for each isotope.Multiply respective decimal by themassAdd all these numbers together.Although this is an "average" you do NOTdivide by the number of components IncorrectMarks for this submission: 0/1.
Question2 Marks: 1
How many neutrons are contained in the nucleus of a 238U atom.
Choose one answer.
a. 92
b. 235
c. 143
d. 146
e. 327
CorrectMarks for this submission: 1/1.
Question3 Marks: 1
Which are isotopes? An atom that has an atomic number of 34 and a mass number of
76 is an isotope of an atom that hasChoose one answer.
A fishing boat accidentally spills 9.0 barrels of diesel oil into the ocean. Each barrelcontains 42 gallons. If the oil film on the ocean is 2.5 x 10 2 nm thick, how many squaremeters will the oil slick cover? Assume that the oil slick forms a cube rather than acylinder.
Choose one answer.
a. 5.7 x10-3 m2
b. 5.7 x10
6m
2
c. 5.7 x107 m2
d. noneof these
Correct
Marks for this submission: 1/1.
Question11 Marks: 1
Because of the high heat and low humidity in the summer in Death Valley, California, avisitor requires about one quart of water for every two miles traveled on foot. Calculatethe approximate number of liters required for a person to walk 20. kilometers in DeathValley.
A hypothetical element is composed of three isotopes with the following masses andabundances: 117.23X (50.0%; 117.23 amu),111.31X (45.500%; 111.31 amu), 135.93X(4.5000%; 135.93 amu). Calculate the average atomic mass of this element. Eventhough it is incorrect to do so, enter your answer to 3 decimal places in order to humorthe computer.
Answer:115.378
Convert percentage to decimal for each isotope.Multiply respective decimal by the
massAdd all these numbers together.Although this is an "average" you do NOTdivide by the number of components CorrectMarks for this submission: 1/1.
Question2 Marks: 1
How many neutrons are contained in the nucleus of a 75Se atom.
A fishing boat accidentally spills 9.0 barrels of diesel oil into the ocean. Each barrelcontains 42 gallons. If the oil film on the ocean is 2.5 x 10 2 nm thick, how many squaremeters will the oil slick cover? Assume that the oil slick forms a cube rather than acylinder.
Because of the high heat and low humidity in the summer in Death Valley, California, avisitor requires about one quart of water for every two miles traveled on foot. Calculatethe approximate number of liters required for a person to walk 20. kilometers in DeathValley.