. We can determine the molar mass of air by considering Nitrogen (N2), Oxygen (O2) and Argon (Ar) make up 78%, 21% and 1% of the atmosphere, respectively. The molar masses of nitrogen, oxygen and argon are 14, 16, 40 g/mole. Compute the molar mass of air [(〖molar mass)〗_air=0.78〖(molar mass)〗_(N_2 )+0.21〖(molar mass)〗_(O_2 )+0.01〖(molar mass)〗_Ar] Remember that you have 2 atoms in N2 and O2. (5 points)

Which common material is an example of a polymer? (25 pts) a. steel b. plastic c. petroleum d. rubbing alcohol

Agroup of students is studying convection current. they fill two identical balloons with the same amount of helium. one balloon is placed in a freezer and the other is in an area with warm air. after 10 minutes, the balloon are released from a height of 1 meter. which of the following to the students most likely observe? a) the warm balloon expands and rises. the cold balloon shrinks and sinks b) the balloon both rise. the cold balloon is larger than the warm balloon c) the cold balloon expands and rises. the warm balloon shrinks and sinks d) the balloon rise at the same rate. both balloons are the same size

Chen drew a diagram to compare the ways in which different organisms obtain nitrogen. which label belongs to the area marked z?