Based on the mass spectrum of a pure element represented above, the average atomic mass of the element is closest to which of the following?

185.7amu

A

186.0amu

B

186.3amu

C

186.9amu

Air can be considered a mixture. which statement does not explain why?

Given the following at 25c calculate delta hf for hcn (g) at 25c. 2nh3 (g) +3o2 (g) + 2ch4 (g) > 2hcn (g) + 6h2o (g) delta h rxn= -870.8 kj. delta hf=-80.3 kj/mol for nh3 (g), -74.6 kj/mol for ch4, and -241.8 kj/mol for h2o (g)

Exit what is the density of an object having a mass of 5.0 g and a volume of 45.0 cm3?