The efficiency of the process is 42%
From the question given above, the following data were obtained:
Useful energy = 250 watt
Wasteful energy = 600 watt
<h3>Efficiency =? </h3>
The efficiency of the process can be obtained as illustrated below:

<h3>Efficiency = 42%</h3>
Therefore, the efficiency of the process is 42%
Learn more: brainly.com/question/2300041
Answer:
D. absolute magnitude and apparent magnitude
Its just Calcium Flouride because as you can see it is an Ionic bond (Ca is metal and fl is a gas usually)
Answer : Noble Gases do not readily form compounds because they are chemically stable with 8 valence electrons.
Explanation :
Noble gases are the chemical elements that are present in group 18 in the periodic table.
The elements are helium, neon, argon, krypton, xenon and radon.
They are chemically most stable except helium due to having the maximum number of 8 valence electrons can hold their outermost shell that means they have a complete octet.
They are rarely reacts with other elements to form compounds by gaining or losing electrons since they are already chemically stable.
Hence, the noble Gases do not readily form compounds because they are chemically stable with 8 valence electrons.