Here’s an arXiv link if you’re hitting a paywall on the paper itself: https://arxiv.org/abs/2001.05141
Physicists captured individual atoms and observed them merge into a molecule
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Re: Physicists captured individual atoms and observed them merge into a molecule
#22For those wondering about why the article says "Two atoms alone can’t form a molecule, it takes at least three to do chemistry", here's another explanation from the reddit thread [0] > Each atom has some amount of energy associated with it. If you just bring two atoms together, the total energy is simply the sum of their individual energies. This state is typically referred to as an excited state. However, the stable…
Can't you make two atoms form a molecule by smashing them together fast enough (where electrons might fly off)?
If you smash them together faster, you just increase their energy, i.e. the opposite of what you want. If electrons fly off, you are likely to be left with an unstable molecule.
Re: Physicists captured individual atoms and observed them merge into a molecule
#23Earlier quoted context omitted.
We still don’t know exactly how catalysts work, because they operate at high temperature and pressure, so it is very hard to study.
This is completely wrong. Many catalysts work at room temperature and pressure and in many cases we understand very well how they work.
And our bodies are full of those. Enzymes are catalysts.
Re: Physicists captured individual atoms and observed them merge into a molecule
#24Earlier quoted context omitted.
That doesn't seem right. Cars have catalysts where the air flows through. Also 2 H2 + O2 -> 2 H2O (+ a characteristic bang :-)) at room temperature and pressure (initially) using a platinum catalyst is shown in school chemistry classes. Just learned on Wikipedia (en/Platinum) that the 2007 Nobel price in Chemistry was awarded for explaining how that works. doi:10.1002/anie.200800480
Car's catalyst work at high temperatures, not at room temperature. In fact, at room temperature they don't work at all, which is exactly the problem with catalysts, they don't work when you start your car. They need to heat with the hot combustion gases to start working, and that takes a while. This is one of the reasons that laboratory's measurements of particles and gases like nitrogen oxides do not apply to real e…
There are many kinds of catalysts beyond materials surfaces. Organic chemists use metal complexes as catalysts in organic synthesis. This is especially important in asymmetric catalysis where you want to form high excesses of one isomer of a molecule, which can have drastically different effects in medicine for example. Catalysis also plays an important role in biology I believe.
Re: Physicists captured individual atoms and observed them merge into a molecule
#25For those wondering about why the article says "Two atoms alone can’t form a molecule, it takes at least three to do chemistry", here's another explanation from the reddit thread [0] > Each atom has some amount of energy associated with it. If you just bring two atoms together, the total energy is simply the sum of their individual energies. This state is typically referred to as an excited state. However, the stable…
Interesting. Is this how catalysts work? By bringing the atoms/molecules reacting together and providing a path for taking away the excess energy more easily?
There are lots of different types of catalysts: Homogeneous (molecule, typically small, in solution), heterogeneous (solid or porous surface) and enzymes (biological molecules.) Many do work by bringing reactants together so that the relevant fragments can combine. Chemical reactions are usually described as going through an energetic transition state and many catalysts stabilize this state so that the reaction can "get over the hill" and become product. Of course, it also stabilizes it for the reverse reaction so the products can become reactants again. The overall equilibrium is not changed. Both reactions speed up. If, however, one extracts the product as it is formed, more product will be formed and hence catalysts are incredibly useful since, by definition, they are not consumed by the reaction - i.e. you get the catalyst back so it can continue to do its work.
Here's a good example of how enzymes catalyze reactions: https://pdb101.rcsb.org/learn/videos/how-enzymes-work
The last 1/3 of this old video from Shell describes how catalytic cracking, a crucial part of oil refining, works. It covers practical reactor considerations, including getting the products out so more are formed and 'poisoning' where a catalyst's efficiency is reduced by contamination and how that's dealt with in a continuous process. https://www.youtube.com/watch?v=hC1PKRmiEvs
Re: Physicists captured individual atoms and observed them merge into a molecule
#26Earlier quoted context omitted.
Can't you make two atoms form a molecule by smashing them together fast enough (where electrons might fly off)?
If you smash them together faster, you just increase their energy, i.e. the opposite of what you want. If electrons fly off, you are likely to be left with an unstable molecule.
But in a covalent bonding you're sharing electrons, which means you need less electrons than in the atom state.
Re: Physicists captured individual atoms and observed them merge into a molecule
#27Earlier quoted context omitted.
If you smash them together faster, you just increase their energy, i.e. the opposite of what you want. If electrons fly off, you are likely to be left with an unstable molecule.
But in a covalent bonding you're sharing electrons, which means you need less electrons than in the atom state.
I sort of see what you are trying to say, but I think you're slightly misunderstanding what is going on. It is true that you are sharing electrons in a covalent bond, but it is not correct to therefore say that you need less electrons than in the atom state. A simple example: say you have to H atoms. Each has one electron. You put them together and form H2, which has two electrons combined. In both cases you need a total of two electrons, in order to have a neutral system. If you change that in any way, you will end up with highly reactive species (e.g. H+, H-, H2+, H2-). H+ is of course just an acid.
What you are probably thinking of, is the fact that if you put NaOH, or HCl in water, you get Na+, OH-, etc., and these are more stable than their neutral counterparts. But this is because they are stabilised by (polar) water molecules. Outside of water (or some other stabilising solvent), Na+, OH-, H+ and Cl- are all very reactive species.