What elements are not balanced in the equation mgo + 2 licl = mgcl2 li2o

This is a balanced equation

An easy way to figure out if the equation is balanced or not is that each element in the R.H.S should be equal to the element in the L.H.S

R.H.S                       L.H.S

Mg = 1                     Mg = 1

O = 1                       O = 1                                              

Li = 2                       Li = 2

Cl = 2                      Cl = 2

As both of them have equal number of elements they are balanced.

1. a)c-14 has two more protons

2. d)they have different numbers of protons, neutrons, and valence electrons; they are all gases at room temperature.

3. c) iron and nickel.