A solution in which [H +] = 10 - 8 M has a pH of ___ and is ___. -8, acidic

6, basic

-6, basic

8, basic

Which of the following produces carbon dioxide? a. plants b. animals c. decomposers d. all of the above

Which of these statements is true about autotrophs, but not heterotrophs? a. they use sugar and oxygen to make carbon dioxide and water.b. they use chlorophyll and oxygen to make carbon dioxide and water.c. they use sunlight, water, and carbon dioxide to make sugars.d. they use sunlight, water, and oxygen to make chlorophyll.

Ihave no idea how to solve these. plus there's another question that is 2) a 10 kilogram meteorite is collected in space and brought back to earth. it is composed of 1.25 kg of uranium-238 and 8.75 kg of lead-206. how many u-238 half lives have passed? what is the approximate age of the meteorite?