Answer:
the mass number decreases by 4 and the atomic number decreases by 2
Answer: 
Explanation:
Lattice energy : It is defined energy released when ions combine together in a gaseous phase to form a compound. it is energy possessed by the crystal lattice of a compound. Denoted by symbol
.
, energy is absorbed while forming of the lattice
, energy is release while forming of the lattice

One mole of sodium ion when combines with one mole chloride ion release 786 kJ of energy.
Lipids I think... just thinking off the top of my head