is it true that droplet of water has

Wendy

Joined Mar 24, 2008
23,415
Atoms are the basic elemental building blocks. They are the smallest particles where you can still have an element, and not a sub atomic particle.

Any atom bigger than helium was likely created in a supernova. It is why people (starting with the late Carl Sagan) likes to say we are made of star stuff, what we are made from is the result of massive stellar explosions, over time.
 

Brownout

Joined Jan 10, 2012
2,390
There are two hydrogen and one oxygen atoms to each molecule of water. So, every water molecule is made up of three atoms. The symbol H20 for a water molecule represents those atoms.
 

Wendy

Joined Mar 24, 2008
23,415
One of the expected outgrowths of technology is the use of atoms as components, and the creation of machines using atoms. This is the basis for the concept of nanotech.

It isn't a major science yet, but the first baby steps have been taken.
 

#12

Joined Nov 30, 2010
18,224
Homework problem for first semester chemistry class:
Given: A pure gold hemisphere of diameter 1/2 mm.
Calculate how may atoms of gold are available on the curved surface.
The answer was somewhere in the millions...or maybe it was in the billions.
Hard to remember after 35 years.

A normal drop of water is a lot larger than 1/2 mm. A water molecule is a lot smaller than a gold atom. The interior of the water droplet also contains molecules. No wonder that a water droplet contains billions of molecules.
 

coldpenguin

Joined Apr 18, 2010
165
Atoms are the basic elemental building blocks. They are the smallest particles where you can still have an element, and not a sub atomic particle.

Any atom bigger than helium was likely created in a supernova. It is why people (starting with the late Carl Sagan) likes to say we are made of star stuff, what we are made from is the result of massive stellar explosions, over time.
I think that is incorrect.
If I remember right, any atom larger than C12 ( natural carbon ) requires a super-nova.
Any atom larger than hydrogen (1 proton) , but smaller than C12, can be created by Fusion, which takes place in normal stars (our star is a first stage SOLar mass 1, so it currently taking two hydrogen atoms, and sticking them together).

An Atom is made of protons and neutrons.
A proton is made up of two up spin quarks and a down-spin quark, and a nutron is made up of two down spins plus an up spin (in theory, in reality you have around 35 quark anti-quark pairs which cancel each other out, however at any 'point' in time, there would be 3 left over.
A neutron ends up as having no charge.
A proton ends up with a charge of '+1'
An electron has a change of '-1' (where + and - are all relative, we have
nothing to actually measure this against. )

An 'ion' could have no electrons. In practice, the number of electrons around an atom should equal the number of protons, so there is no ionisation.

In a 'stable' atom, the number of protons should be almost equal to the number of neutrons.
Each element has a different number of protons. The number of protons defines which element it is. However, some atoms might have more or less neutrons than others. If the balance of neutrons to protons is too far out, a particle might change from one to the other, releasing the energy difference (between an up and a down-spin quark, which have the same energy, in theory, but not in practice).

Normally.....
Hydrogen has 1 proton. Helium has two protons.
Oxygen has 8 protons (if I remember right).

But, you can get heavy hydrogen, one proton plus one neutron. This would be what the heavy is in heavy water.
 

JDT

Joined Feb 12, 2009
657
It turns out that 1 gram of water has about 3X10^22 molecules so about 9X10^22 atoms. That's a 9 with 22 zeros after it.
Is that more than than the number of grams of water in all the oceans of the world combined? Anyone know?

If so...

If you somehow marked all the molecules in your gram of water (a thimble full) and poured it into the sea. Mix up all the oceans (might take millions of years). Then sampled a gram of sea water anywhere in the world. You would find at least one of your molecules there.
 

Austin Clark

Joined Dec 28, 2011
412
Is that more than than the number of grams of water in all the oceans of the world combined? Anyone know?

If so...

If you somehow marked all the molecules in your gram of water (a thimble full) and poured it into the sea. Mix up all the oceans (might take millions of years). Then sampled a gram of sea water anywhere in the world. You would find at least one of your molecules there.
I just tried my hand at the math, and found that (on average) you'd have to pull 35 to 40 grams of sea water to find one of the marked molecules, or 2.7% chance per gram, which is actually extremely surprising.

Someone wanna verify that?
 
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