Every atom is useful.Example is oxygen.
so that we can easy to know the measuring mass of an atom
Most useful and more useful.
more useful, the most useful
more useful, most useful
The nucleus of an atom represents most of an atom's mass.
um... I'm pretty sure it's more helpful and the most helpful?
The frequency of the atom defines a second and used for international time.
Silence is most useful when broken.
most useful
more useful and most useful
more useful, most useful
What the most useful machine is, is a matter of opinion. Some would argue that the wheel is the most useful machine, and others would argue that the lever is the most useful.