Representing Air Particles

To make our lives easier, we are going to agree to represent those 900,000,000,000,000,000,000 air particles with just 35 dots. So should our syringe look like this?

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Since air is a gas and a gas will fill up any space, the air particles in the syringe should be evenly distributed. But what if we only pulled the plunger up to 25? How would we represent the number of air particles in the syringe then? In that case, we would represent the air particles with 25 dots.