oxygen is in gaseous state at this temperature
 
        
             
        
        
        
Protons and neutrons are located in the nucleus of the atom while the electrons move in the trajectory of the shell
<h3>Further explanation  
</h3>
Isotopes are atoms whose no-atom has the same number of protons while still having a different number of neutrons.  
So Isotopes are elements that have the same Atomic Number (Proton)  
Isotopes of Helium : helium-3 and helium-4
protons = 2
electrons=protons=2
neutron=mass number-atomic number=3-2=1
protons = 2
electrons=protons=2
neutron=mass number-atomic number=3-2=1
protons = 2
electrons=protons=2
neutron=mass number-atomic number=4-2=2
Protons and neutron in the nucleus, electrons in the shell
 
        
             
        
        
        
I can’t read ? This what does it say
        
             
        
        
        
The alloy has a density of 21.186g/cc. So for a kilogram or 1000 grams/21.186 g/cc= 45.7 cc. So the answer is 45.7 cc of the allow to make up a kilogram which shows that the density of the allow can be used to calculate the volume of a larger mass ie the kilogram.