Answer:
false evaporation is change of state
boiling point is temperaturw of liquid
Answer:
A = 65.46 u
Explanation:
Given that,
The composition of zinc is as follows :
Zn-64 = 48.63%
Zn-66 = 27.90%
Zn-67 = 4.10%
Zn-68 = 18.75%
Zn-70 = .62%
We need to find the average atomic mass of the given element. It can be solved as follows :

So, the average atomic mass of zinc is 65.46 u.
Answer:
Explanation:
In S₈ , there are 8 single bonds which breaks up first . Energy absorbed
= 8 x 240 = 1920 kJ
In S₈ four double bonds of S₂ are formed . Let bond energy be x . In this process energy will be released . energy released in four S₂ molecules formed = 4 x
Given
1920 + 4x = 239
4x = 239 - 1920
x = - 420.25 kJ .
So bond energy of S₂ = 420.25 kJ .