(a) MgO has a higher lattice energy than NaF-why?
(b) What is the geometry of the ionic crystal if the value of `r_(+)//r_(-)` is in the range of 0.225-0.414?

MgO has higher lattice enegy than NaF. Why?

What is the geometry of the ionic crystal if the valeu of r_(+)//r_(-) (radius ratio of the monovalent cation and anion) is in the range 0.225-0.414?

If p, q, r be the roots of the equation x^3 + ax - b = 0 , then the value of pqr will be

If a and b(!=0) are the roots of the equation x^2+a x+b=0, then find the least value of x^2+a x+b(x in R)dot

For an ionic crystal r+/r 0.414- 0.732 the co-ordination number be.

For a value of radius ratio between 0.732-1.0, what is the co-ordination number and geometry of crystal ?

For a value of radius ratio between 0.414 - 0.732 , what is the co-ordination number and the geometry of the crystal?

Assertion :- In NaCl crystal each Na^+ ion is touching 6 Cl^(-) ions but these Cl^(-) ions do not touch each other. Reason :-The radius ratio r_(Na^+)//r_(Cl^(-)) is greater than 0.414, required for exact fitting.

If the equation (x-p)(x+q)+r=0 is expressed in the form ax^(2)+bx+c=0(ane0) then the value of b is

If alpha is the root (having the least absolute value) of the equation x^2-b x-1=0(b in R^+) , then prove that -1ltalphalt0.