Answer:
<h2>0.5 moles</h2>
Explanation:
To find the number of moles in a substance given it's number of entities we use the formula

where n is the number of moles 
N is the number of entities
L is the Avogadro's constant which is 
6.02 × 10²³ entities
From the question we have

We have the final answer as
<h3>0.5 moles</h3>
Hope this helps you
 
        
             
        
        
        
Answer: I’m not one hundred percent sure, but based off of what I know, I believe it is most likely “So it’s images aren’t distorted by the Earth’s atmosphere.”
Explanation:
 
        
             
        
        
        
<u>Answer:</u> The correct answer is Option 4.
<u>Explanation:</u>
There are three sub-atomic particles present in an atom. They are: electrons, protons and neutrons.
Protons constitute in each and every atom.
The charge on proton is of equal magnitude as that of electron but having opposite sign. Proton carry a positive charge and electron carry a negative charge.
Protons and neutrons, both determine the mass of an atom.
Mass of 1 proton = 1.007276 u
Mass of 1 neutron = 1.008664 u
Mass of 1 electron = 0.00054858 u
Mass of proton is almost same as that of neutron but is more than the mass of electron.
Hence, the correct answer is Option 4.
 
        
             
        
        
        
<span>Helium = 1 
Carbon = 8 
Nitrogen = 8 
Strontium = 52 
Tellurium = 71 
If you look on a periodic table, on each element there is a number on
the top left. This represents the number of protons in an atom. Protons
have a mass of 1 (in relative to Carbon-13) 
If we take nitrogen-15 for example; The number 15 tells you that the
isotope has a mass of 15. Now if you look on the periodic table,
Nitrogen has a proton number of 7. Only protons and neutrons have a
mass, electrons are considered to be negligable. Therefore the number of
neutrons Nitrogen-15 contains is 15 - 7 = 8 </span>