Answer:
w = -531 kJ
1. Work was done by the system.
Explanation:
Step 1: Given data
- Heat gained by the system (q): 687 kJ (By convention, when the system absorbs heat, q > 0).
- Change in the internal energy of the system (ΔU°): 156 kJ
Step 2: Calculate the work done (w)
We will use the following expression.
ΔU° = q + w
w = ΔU° - q
w = 156 kJ - 687 kJ
w = -531 kJ
By convention, when w < 0, work is done by the system on the surroundings.
Answer:
Explanation:
Efficiency of the electric power plant is 
Here Temperature of hot source 
and Temperature of sink 
Hence the efficiency is
Now another formula for thermal efficiency Is

Here QI is the of heat taken from source 100 MJ ; Q2 of heat transferred to the sink (river) to be found
W is the of work done and W = QI -Q2
Hence From

Hence the of heat transferred to the river Is 
Question
<em>Given the noble gas configuration of an element: [Ar] 4s2, 3d5, what is the element?
</em>
Answer:
<em>B.) Argon</em>
Hope this helps!
The semifluid or hot fluid substance within or below the crust of the Earth from which lava and other igneous rock are produced by cooling is known as magma.
The temperature and pressure elevate with depth, finally reaching to a level wherein the strongest rock is melted, transforming into magma. When the magma comes into contact with water, it instantly gets transformed into a rock, that is, the outside solidifies briskly, and the inside of it gets cold.