Answer : 
Explanation : In the molecule of
the hydrogen bonding forces tend to resist any phase transition form liquid state to gaseous phase, and these hydrogen bonding forces are greater usually when the hydrogen is bound to an electronegative atom like chlorine, fluorine,oxygen,etc. This then lowers the viscosity of the compound.
Answer: Adiabatic process is a process in which <u>heat</u> is constant
Explanation:
The processes in which temperature remains constant is called isothermal process.
The process in which Volume remains constant is called isochoric process.
The process in which pressure remains constant is called isobaric process.
The process in which no heat is gained or lost by the system, Hence heat remains constant is called as adiabatic process.
Thus option d) heat is correct
Answer:
(a) 
(b)


(c) 
Explanation:
Hello,
(a) In this case, with the given formula we easily compute the mass of gold contained in the sovereign as shown below:

(b) Now, by knowing the density of gold and copper, 19.32 and 8.94 g/cm³ respectively, we compute each volume, by also knowing that the rest of the coin contains copper:


(c) Finally, the volume is computed by dividing the total mass over the total volume containing both gold and copper:

Best regards.