Tropical or warm air masses form in the tropics and have low air pressure. 
polar or cold air masses form north of 50 degrees north latitude and south of 50 degrees south latitude
        
             
        
        
        
I would say the answer is emissions. These are the particles that are not supposed to be present in air but due to the production of different substances from humans daily activities these substances go with the air we breath. Hope this helped.
        
             
        
        
        
Answer:
A scientific theory is a widely accepted belief on why something happens in the natural world while a scientific law is proven to a fact that shows what happens.
Explanation:
 
        
             
        
        
        
Explanation:
Since liquid isopropanol is a polar liquid and water is also a polar solvent. So, when both of them are added together then according to the like dissolves like principle they get dissolved. 
At the molecular level, the polar molecules of isopropanol get attracted towards the polar molecules of water at the surface of water.
As a result, water molecules get surrounded by isopropanol. Thus, water molecules enter the solution and evenly spread into the solution. 
 
        
                    
             
        
        
        
One of the pieces of evidence of the big bang theory where that celestial objects are scattered in the universe because of an explosion that supports the idea of the big bang.
<h3>What is the big bang?</h3>
The big bang is how astronomers explain the way the universe began. 
The evidence that I've gathered from the widget that demonstrates that the universe is expanding is that galaxies and other celestial objects are moving away from each other, which is also one of the evidence of the big bang theory where the celestial objects are scattered in the universe because of an explosion that supports the idea of the big bang.
Learn more about the big bang here:
brainly.com/question/18297161
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