What is the mole ratio of  to Fe? if oxygen it is 4:3 Fe3O4
We know that density of olive oil = 0.93 g/mL
Given that mass of olive oil = 1.4 kg or 1400 g because 1000 g = 1.0 kg
From the definition of density;
Volume = mass/ density
= 1400 g/ 0.93 g/mL
=1505 mL
There is a shortcut trick while doing such fill in the blanks of nuclear reactions of hydrogen and helium
Let a,b,care elements of set N
Now
for our question
Hence b=4-3+1=1+1=2
So
The missing place should b e deuterium of heavy water
In nuclear reactions energy is released so it's mentioned on product side not reactant side