A percent composition problem: A 1.836-g sample of coal contains 1.584 g of C.
What is the percent (%) weight of carbon in this sample of coal?

Which of the following are false concerning microbes? a. microbes generate oxygen through photosynthesis.b. the primary role of microbes on the planet involves causing disease in animals and humans.c. microbes produce vitamins in the intestines.d. microbes play a role in breaking down waste and decomposing dead organisms.

The two tubes contain bromothymol blue. after 24 hours, what will the color of the water be in tube b? a. green (it won't change) b. yellow c. blue d. colorless (clear)

Which statement about relative potential energy of electrons is correct? a. an electron in the 2 p orbital of the second electron shell has more potential energy than an electron in the 2 s orbital of the second electron shell. b. an electron in the 2 p orbital of the second electron shell has more potential energy than an electron in the 3 p orbital of the third electron shell. c. an electron in the 3 p orbital of the third electron shell has more potential energy than an electron in the 2 p orbital of the second electron shell.