Answer:A
Explanation:
The solar system consist of the sun, the planets, stars and other objects. The chemical composition of the Sun consist mainly of Hydrogen and helium.
The sun is the largest object in the Solar system, it comprises nearly all the matter in the Solar System, Also the largest planet after the Sun are Jupiter and Saturn are giant planets forming almost the remaining matter of the solar system.
Like the Sun, the mass of Jupiter and Saturn are composed of roughly 98% hydrogen and helium with 2% of all the other elements combined. 
 
        
             
        
        
        
Answer:
Explanation:
The main task here is that there are some missing gaps in the above question that needs to be filled with the appropriate answers. So, we are just going to do rewrite the answer below as we indicate the missing gaps by underlining them and making them in bold format.
SO; In the quantum-mechanical model of the hydrogen atom.
As the n level increases. the energy <u>increases</u> and thus levels are <u>closer to </u>each other. Therefore, the transition <u>3p→2s</u> would have a greater energy difference than the transition from <u>4p→3p.</u>


 
        
             
        
        
        
Answer:

Explanation:
Hello,
In this case, it is widely known that when measurements with different significant figures are put under mathematical operations, the final result must be displayed with the same amount of significant figures of the shortest measurement, thus, due to the fact that 5.5 g has two significant figures only the result is consequently shown with two significant figures as well as shown down below:

By rounding the first six to seven due to the fact that the next six is greater than five, according to rounding rules, the result is:

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