There is only one atom of each element in the molecule.
For example:
* HCl (hydrochloric acid) contains one hydrogen atom (H) and one chlorine atom (Cl).
* CO (carbon monoxide) contains one carbon atom (C) and one oxygen atom (O).
* NaCl (sodium chloride) contains one sodium atom (Na) and one chlorine atom (Cl).
It's important to remember:
* The absence of numbers doesn't necessarily mean the compound is simple. It only indicates that there's a single atom of each element present.
* Many compounds with more complex structures have formulas without numbers.
Let me know if you have any other questions!
