I think C. Ionic compounds are very difficult to break apart because they are fully negative or positive charges, like magnets.
Answer:
Wavelength, 
Explanation:
We have,
Velocity of the object, 
Mass of the object, 
It is required to find the wavelength of the object. The relation between wavelength and velocity of the object is given by :

h is Planck's constant

So, the wavelength of the object is
.