how do scientists know theres trillions of molecules in water

Question

I randomly had a thought in my head and now im curious, how do scientists know that atleast trillions of molecules in let’s say a water bottle is an accurate number? Because its says that it is a factual statement but how did they get to the point where they knew it was actually atleast in the trillions Thanks.

Edit: thank you so much for the answers guys!! 🙂

In: 0

Answer 1

1 cubic centimetre of water holds 3.345 x 10^(22) molecules of water.

That’s 33,450,000,000,000,000,000,000 molecules (read as thirty-three sextillion, four-hundred-and-fifty quintillion). In the space less than a 6-sided dice.

So saying that a 1 litre bottle of water holds trillions of molecules, while technically correct, is misleading.

1 litre of water is 1000 cubic cms, so that’s 3.345 x 10^(25) or

33,450,000,000,000,000,000,000,000 molecules, or thirty-three septillion, four-hundred-and-fifty sextillion.