Answer:
Subscripts are small numbers that tell us the number of each type of atom in a compound
If there is no number stated then it automatically means there is one atom present
Coefficients are big numbers in front of formulas that tell us we have more than 1 molecule present
Using the example of 2H₂O
The coefficient (2) multiplies the number of atoms of each element in this formula. For hydrogen 2 × 2 = 4 hydrogen atoms and 2 × 1 = 2 oxygen atoms