Answer:
By atomic number?
Explanation:
fingers crossed its right :/
 
        
             
        
        
        
The formula of density is mass / volume
This means that
- high mass, low volume = high density
- high mass, high volume = so-so
- low mass, high volume = low density
From the graph shown, 
D has the lowest density because it has low mass yet high volume.
        
             
        
        
        
Answer: The pH of the solution is 11.2
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.

where,
n = moles of solute
 = volume of solution in ml
 = volume of solution in ml
moles of  =
 =  (1g=1000mg)
         (1g=1000mg)
Now put all the given values in the formula of molality, we get


pH or pOH is the measure of acidity or alkalinity of a solution.
pH is calculated by taking negative logarithm of hydrogen ion concentration.
![pOH=-\log [OH^-]](https://tex.z-dn.net/?f=pOH%3D-%5Clog%20%5BOH%5E-%5D)

According to stoichiometry, 
1 mole of  gives 2 mole of
 gives 2 mole of  
 
Thus 0.0298 moles of  gives =
 gives = moles of
 moles of  
 
Putting in the values:
![pOH=-\log[0.0596]=2.82](https://tex.z-dn.net/?f=pOH%3D-%5Clog%5B0.0596%5D%3D2.82)



Thus the pH of the solution is 11.2
 
        
             
        
        
        
Answer:
The group 18 elements are helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). These elements are non-reactive and are called noble gases as they have their outermost orbit complete. Due to stable electronic configuration they hardly react with other elements.The name comes from the fact that these elements are virtually unreactive towards other elements or compounds.The group 18 elements are called noble or inert gases. As the name suggests these are inert because chemically they are very less reactive or not at all reactive.The full valence electron shells of these atoms make the noble gases extremely stable.