<span>The layer of rock above it might contain the fossil of a fish as, according to the law of faunal successsion, this was the first animal to evolve after shelled organisms. In sedimentary rock, animals that evolved later could only be found in layers above those from an earlier time.</span>
The boiling point depends on the strength of the intermolecular forces holding the molecules together. Greater the force, higher is the boiling point.
The intermolecular force increases in the order shown below:
ion-ion > H-bonding > dipole-dipole > London dispersion
CH3CN is a polar molecule with strong dipole-dipole forces
CH3CH2CH3 is non-polar held by london dispersion
Ar exist as a gas. It will have a lowest boiling point
Thus the order of decreasing b.pt is:
CH3CN > CH3CH2CH3 > Ar
I would say copper, silver, and tin, since an alloy is a mixture of metals and metalloids.
1 mole of NH42SO4 contains 42 moles of H. We take the 42 moles of H and multiply that times Avogadro's number (6.02x10^23) and get 2.5284x10^25 atoms of hydrogen