Yes because you have to use fuel to drive that's my guess
Reactants I think........
For that you have to use the Aufbau principle
For example, writing the electronic configuration of Fe(28)
I recommend that you memorize the aufbau principle. Once you learn it, you don’t need anything else except the atomic number of the element to write it’s electronic configuration.
Water: pH7
Lemon juice:pH2
Milk: pH6.5
Vinegar: pH2.4
Washing up liquid: pH5-6
:)