Answer:
A. Dark-colored moths become common after tree trunks become
dark.
Explanation:
I took the test
Answer:
The molar mass of dry air = 28.94
Density = 1.29
Explanation:
Mm of N2= 28, Mm of O2= 32, Mm Ar= 39.9
78% of N2 by mole give = 0.78×28= 21.84
21% of O2 by mole give = 0.21× 32= 6.72
1% of At by mole give = 0.01× 39= 0.39
Hence overall molecular weight of air = 21.84+6.72+0.39= 28.94
Density = m/ v,
1- mole of air occupy 22.4dm^3 volume
Density= 28.94/22.4= 1.29
