Answer:
Explanation:
At constant pressure Thermal energy always moves from a greater energy level to a lesser energy level, laws of thermodynamics prove that.
Nature always likes to attain equilibrium either it's movement of heat energy or flow of water from higher region to lower region. The first and second law of thermodynamics are profe of that, the first law says that the total energy of universe is Constant. Energy can not be destroyed it always changes from one form to another, by work and heat. The second law explains why thermal energy moves from a greater energy level to a lesser energy level, it deals with the change in entropy of a system and surrounding and states heat flows from hot environment to cold environment.
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Gas chromatography is a type of <span>chromatography that is usually used in analytic chemistry in order to analyze and separate the compounds that can be vaporized without decomposition.
Based on this:
</span><span>Gas chromatography can be useful in determining the chemical composition of paint.</span>
Answer: The balanced equation for the complete oxidation reaction that occurs when methane (CH4) burns in air is 
.
Explanation:
When a substance tends to gain oxygen atom in a chemical reaction and loses hydrogen atom then it is called oxidation reaction.
For example, chemical equation for oxidation of methane is as follows.
Number of atoms present on reactant side are as follows.
Number of atoms present on product side are as follows.
To balance this equation, multiply 
by 2 on reactant side. Also, multiply 
by 2 on product side. Hence, the equation can be rewritten as follows.
Now, the number of atoms present on reactant side are as follows.
Number of atoms present on product side are as follows.
Since, the atoms present on both reactant and product side are equal. Therefore, this equation is now balanced.
Thus, we can conclude that balanced equation for the complete oxidation reaction that occurs when methane (CH4) burns in air is .
<h2>Answer : Electromagnetic energy</h2><h3>Explanation :</h3>
The solar panel usually combines multiple photo voltaic cells. Electromagnetic energy is used to power a solar panel. As the electromagnetic energy or rather radiations from the sun reaches to Earth in the form of radiation which is then collected by these photo voltaic cells. As the term solar energy simply suggests that the energy is coming from the sun. Thus, electromagnetic energy coming from the sun was produced when electric charges inside the sun change their potential energy.
Answer:
19. 1, 2, 3, 4, 5, 6, 7, 8
20. Li=1+, Be=2+, B=3+, C=4+
21. N=3-, O=2-, F=1-
Explanation:
