Microorganisms have a major role in maintaining soil biodiversity. They recycle nutrients in ecosystems and decompose organic matter in soil. Organic matter contains dead and living plant and animal materials. Microorganisms convert these materials into simpler compounds that maintain soil quality and help with plant growth. Which solution could best help to restore or increase microorganisms and soil biodiversity?
A.
adding manure or compost to the soil
B.
spraying chemical weed-killers and fertilizers on the soil
C.
removing all ground-covering plants from the soil
D.
adding sewage containing synthetic materials to the soil

How does chemistry affect our world? a. chemicals makes our world more polluted. b. chemicals keeps us healthy. c. chemicals can or hurt our world. d. chemicals make our world safe to live in.

13. calculate the initial concentration (before precipitation) of carbonate ions after the addition of each 0.05 ml of solution b to the 1.00 l beaker of solution a. divide the work among group members and write the answers in the table in model 3. assume the volume change as solution b is added is negligible. 14. notice the initial concentrations of zn2+ - and cu2+ in the table in model 3. a. explain how these were obtained from the data in model 2. b. as solution b is added and precipitates form, do these initial concentrations change? 15. use the data in model 2 to indicate the presence of precipitate (either znco3 or cuco3) after each 0.05 ml addition of solution b in model 3. 16. use the initial concentrations of carbonate ions and zinc ions to calculate the reaction quotient, qsp for the zinc carbonate scenarios in model 3. divide the work among group members and write the answers in the table in model 3. 17. use the initial concentrations of carbonate ion and copper(ii) ions to calculate the qsp for the copper(ii) carbonate scenarios in model 3. divide the work among group members and write the answers in the table in model 3.

8) a mixture of he, ne and ar has a pressure of 7.85 atm. if the ne has a mole fraction of 0.47 and 8) ar has a mole fraction of 0.23, what is the pressure of he? a) 4.2 atm b) 3.7 atm c) 5.5 atm d) 2.4 atm e) 1.8 atm