Orbitals am only hold two electrons each, so 3 orbitals can hold 6 electrons
Answer: The coefficients for the given reaction species are 1, 6, 2, 3.
Explanation:
The given reaction equation is as follows.

Now, the two half-reactions can be written as follows.
Reduction half-reaction: 
This will be balanced as follows.
... (1)
Oxidation half-reaction: 
This will be balanced as follows.
... (2)
Adding both equation (1) and (2) we will get the resulting equation as follows.

Thus, we can conclude that coefficients for the given reaction species are 1, 6, 2, 3.
Answer:
Its quite vague, instead you could say an atom is the smallest building block which further consists of subatomic particles like protons, neutrons and electrons :)
Hope thi helps :) and I'd appreciate if you'd mark brainliest because ive been stuck on the same rank for quite a long time :(