The data in the table below was collected by researchers to investigate the oxygen concen- tration of water in a lake. Data was collected from the location in the lake at the same time every day repeatedly over a six-day period. Day A B с D 9.04 ppm Calculate the mean of the sample data. 0.63 ppm 1.65 ppm Day 1 1.12 ppm Day 2 Day 3 Day 4 Day 5 Day 6 Oxygen Concentration (ppm) 1.2 21 20 1.7 1.4 1.5

Explain why a particle elutriator is not considered a particularly useful method for removing particles that cause health effects from an airstream.

Estimate the chronic daily intake of 1,1,1-trichloroethane from exposure to a city water supply that contains a 1,1,1-trichloroethane concentration equal to the drinking water standard of 0.2 mg ・ L−1. Assume the exposed individual is a child who consumes water at the child rate for 5 years, that she swims once a week for 30 minutes, and that she takes a short (10 minute) bath every day. Assume her average age over the exposure period is 8. Assume that the average air concentration of 1,1,1-trichloroethane during the bath is 2 μg ・ m−3. Assume the dermal uptake from water (PC) is 0.0060 m ・ h−1 and that direct dermal absorption during bathing is no more than 50 percent of the available l,1,1-trichloroethane because she is not completely submerged.

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Norei Alizay t tntio tu NealHi KuluuGuluut 1O8 Name: Thermometer Worksheet Write the temperature reading to the nearest tenth degree underneath each of the examples below. IS "F 1018 316 317 318 319 4h t412 1. Reading: 96 98.6 00 14. 36 317 318 319 40 4he 42 4h E 42 2. Reading: . 96 1.918.6...J00I 14 16 "FL. 1018 316 37 318 319 40 4h t 42 ....... 3. Reading:. 98.6 700 316 317 318 319 40 4ht42 4. Reading: . 316 317 318 39 4h e 42 5. Reading:. 96 1 98.6. j00 12..14J. 6 F 108 Immi 1 316 317 318 319 404h E 42 6. Reading: 96 | 98.G 0 316 317 318 319 410 4h t42 7. Reading: . 96 | 98.6l 10 16 FL 1018 316 317 318 319 8. Reading: 916 1. 98...y00...ul 316 317 318 319 4h t42 9. Reading: 916 98.d 100 12.1. 14|6 F 1018 316 317 318 39 40 4h t42 eading: .

What is the purpose of the respirometer with just rocks (the thermobar)? What conditions would cause movement of the water bubble in the pipette of this respirometer during the experiment?

a 139 ng sample of radioactive material has a half life of 4.2 days how many ng of radioactive material is left after 3 half lives ?

The atmospheric ratio of peroxyacetic nitric anhydride (PAN) to PAN + inorganic nitrite varies from less than 0.1 to 0.9. High values of the ratio are associated with photo chemically aged air masses, situations where precipitation has recently occurred, and situations were unusually high nighttime nitrogen oxide concentrations are found. What do these observations tell us  about the factors affecting the relative rates of formation and removal of nitrogen oxide compounds?

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