Answer:
electron-electron repulsion
Explanation:
When electrons add into valence shell of neutral elements, the element assumes a negative oxidation state. With this, the number of electrons having (-) charges will be larger than the number of protons having positive (+) charges. As a result, the extra electrons repel one another (i.e., like charges repel) and a larger radius is the result.  
In contrast, when cations are formed, electrons are removed from the valence level (oxidation) producing an element having a greater number of protons than electrons. The larger number of protons will function to attract the electron cloud with a greater force that results in a contraction of atomic radius and a smaller spherical volume than the neutral unionized element.     
To visualize, see attached chart that shows atomic and ionic radii before and after ionization of the elements.   
 
        
             
        
        
        
What do you mean by that? Can you explain further?
        
             
        
        
        
Answer:
Nitrogen atom is small in size than phosphorus thus the bond between its nucleus and valence electrons are stronger than phosphorus.
Hope it helps...。◕‿◕。
 
        
             
        
        
        
Given that the volume and amount  of water are kept constant,
P/T = constant
P₁/T₁ = P₂/T₂
Normal atmospheric pressure is 746 mmHg and normal boiling point of water is 100 °C.
746/100 = 589/T₂
T₂ = 79.0 °C
        
             
        
        
        
Answer:
If we subtract the atomic number from the atomic mass: atomic mass - atomic number = number of protons + number of neutrons - number of protons. Thus we get the number of neutrons present in an atom when we subtract the atomic number from the atomic mass.
Explanation: hope this helps???