[Erik Moeser]

Erik  asked the Naked Scientists:

Dear Dr. Chris:   My brother and I have come to a "conclusion", and
have a high degree of  confidence in the following statement:

"The molecules in a single drop of water, if diluted evenly throughout the "seven seas" (the oceans of the world), would result in a density of one molecule (from the drop) per litre of sea water."

This is astounding!  Please find below our assumptions and maths.  I
hope you can confirm the correctness of the assumptions and the accuracy of the maths!

This is useful in illustrating the mind-boggling tiny size of molecules.

Erik Moeser
Menomonee Falls, WI

Robert Moeser
Boston, MA

One litre = 24,000 drops

The volume of the sea is 1.4 billion cubic kilometres

18g (or cc) of water = one mole

Number of molecules per drop:  1000/18 (6.022X10 to the 23rd)/24000 = 1.39 X 10 to the 21st

Number of litres in the oceans:  1.4  X  10 to the 9th X  10 to the
ninth  =  cubic metres of sea water, X 1000 = litres of sea water = 1.4 X 10 to the 21st

What do you think?

[Evie]

Doesn't a liter of water have 20,000 drops?

[Erik Moeser]

I have seen the number 20.000 which would result in even more molecules per drop.  However I have also seen the 24,000 number.  I think drops come in different sizes and therefore not a standard precise volume for one.

[chris]

24,000 equates to a volume of about 0.03ml, which not unreasonable for a droplet size.

Chris

[Rodin1880]

VOTED BEST ANSWER?!?
The answer is ridicule-us...

Lets call molecules "bactz" and drops "cubies" and Litres "obgos"

A cubie contain a certain number of bactz, Obgos contain a certain number of cubies, and oceans contain a certain number of Obgos

Regardless the size of the cubies, or number of cubies in an obgos, it's all relative when you are considering bactz distribution throughout...

Give the kids credit for thinking...

[chris]

@Rodin1880 - I'm not at all sure what you are getting at. The calculation applied above - which is a good illustration of how to make an informed and valid "guesstimate" seems very reasonable to me. What is your objection?

[Petrochemicals]

Think of this then, a litre of sea water should have some radioactive materials from fukushima

https://www.japantimes.co.jp/news/2018/03/29/national/seven-years-radioactive-water-fukushima-plant-still-flowing-ocean-study-finds/#.XFr18tGnxTs