What is the energy of a photon having a wavelength of 4.94 ✕ 10-8 m?

Which is a character of nuclear fusion but not nuclear fission

When determining the shape of a molecule, it is important to draw a lewis dot structure first in order to see the total number a. electrons within the moleculeb. bonding and unshared pairs around central atomc. unshared pair within the molecule( i really need it )

Calculate the number of molecules present in 0.750 mol of mgo.