Answer:Transcribed image text: on 54 of 54 8 Review Constants 1 Periodic Table On its website, the EPA claims that sulfur dioxide levels have fallen by 85% between 1990 and 2016. Calculate the percent decrease between these two years to determine whether this claim accurate. Express your answer as a percentage. View Available Hint(s) ? ΑΣφ percent decrease % Submit Part B The EPA air quality standard for SO2 is 75 ppb. In what year did the average U.S. SO2 concentration begin to meet this standard? Express your answer as a year, in the format YYYY. View Available Hint(s) first year 75 ppb standard met: Submit Part C 54 of 54 Review Constants 1 Periodic Table Part What is the percent by mass of S in SO2? Express your answer as a percentage to four significant figures. View Available Hint(s) IVO AE ? % Submit Part D A 100 m room with an SO2 concentration of 75 ppb contains about 0.017 g SO2. How many sulfur atoms does it contain? Express your answer to two significant figures. View Available Hint(s) VE] ΑΣφ ? atoms Submit Sulfur dioxide is a pollutant emitted primarily by coal-burning power plants and industrial smelters. Sulfur dioxide in air affects the respiratory system in humans and is the main cause of acid rain. Thanks to the Clean Air Act and its amendments, sulfur dioxide levels in the United States have dramatically fallen over the past 30 years. The graph below shows the mean sulfur dioxide levels from 136 measuring sites in the United States for the period 1990 to 2016. Examine the graph and answer the questions that follow. Sulfur Dioxide Mean Concentration 140 120 100 80 SO, Concentration (ppb) 60 40 20 0 1990 1995 2000 2005 2010 2015 Year 2020
Step-by-step explanation:
Transcribed image text: on 54 of 54 8 Review Constants 1 Periodic Table On its website, the EPA claims that sulfur dioxide levels have fallen by 85% between 1990 and 2016. Calculate the percent decrease between these two years to determine whether this claim accurate. Express your answer as a percentage. View Available Hint(s) ? ΑΣφ percent decrease % Submit Part B The EPA air quality standard for SO2 is 75 ppb. In what year did the average U.S. SO2 concentration begin to meet this standard? Express your answer as a year, in the format YYYY. View Available Hint(s) first year 75 ppb standard met: Submit Part C 54 of 54 Review Constants 1 Periodic Table Part What is the percent by mass of S in SO2? Express your answer as a percentage to four significant figures. View Available Hint(s) IVO AE ? % Submit Part D A 100 m room with an SO2 concentration of 75 ppb contains about 0.017 g SO2. How many sulfur atoms does it contain? Express your answer to two significant figures. View Available Hint(s) VE] ΑΣφ ? atoms Submit Sulfur dioxide is a pollutant emitted primarily by coal-burning power plants and industrial smelters. Sulfur dioxide in air affects the respiratory system in humans and is the main cause of acid rain. Thanks to the Clean Air Act and its amendments, sulfur dioxide levels in the United States have dramatically fallen over the past 30 years. The graph below shows the mean sulfur dioxide levels from 136 measuring sites in the United States for the period 1990 to 2016. Examine the graph and answer the questions that follow. Sulfur Dioxide Mean Concentration 140 120 100 80 SO, Concentration (ppb) 60 40 20 0 1990 1995 2000 2005 2010 2015 Year 2020
Answer:
Step-by-step explanation:
= 5
do cross multiplication
3x + 5 = 5(2x + 7)
3x + 5 = 10x + 35
5 - 35 = 10x - 3x
-30 = 7x
-30/7 = x
20 A
since there are 7 angles given it means that the polygon is heptagon as heptagon has 7 sides.
sum of interior angle of heptagon = (n-2)*180
(7-2)*180
5*180
900
Now ,
110 + 90 + 150 + 102 + 110 + 170 + x = 900
732 + x = 900
x = 900 - 732
x = 168 degree
20 B
since 5 angles are given it means that the polygon is pentagon as pentagon has 5 sides.
sum of interior angles of a pentagon = (n-2)*180
(5-2)*180
3*180
540 degree
Now ,
110 + 95 + 120 + 114 + x = 540
465 + x = 540
x = 540 - 465
x = 75 degree
21
let one rational number be x
according to the question,
1/7 * x = 2
x/7 = 2
do cross multiplication
x = 14
Answer: 7.5 cups of sugar.
Step-by-step explanation:
Add all of the above:
2+1.5+0.5+3+1.5= <u>8.5 cups of sugar</u>
<u></u>
Since Zach only needs 1 cup of sugar, subtract 1 from 8.5.
Therefore, your answer is <u>7.5 cups of sugar.</u>
