12.Calculate the wavelength of an object moving with a velocity of 5 x105 m s-1
.(h = 6.6x10-34 J s; mass of the object = 4 x10-22 kg)

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 .      

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."