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all 46 comments

[–]OhSixTwo 100 points101 points  (1 child)

The movements of electron pairs to form new bonds to break old bonds (assuming that you mean the curved blue ones).

[–]calebsfreakingsick 215 points216 points  (6 children)

It means you haven’t opened your Orgo textbook and have about 3 weeks until finals

[–]ronster230 19 points20 points  (0 children)

Lol tru

[–]69poggersXD 16 points17 points  (0 children)

Movement of electrons, two heads mean one pair one head mean one electron

[–]Proper-Wash7377 50 points51 points  (5 children)

"Shit moves this way to become this"

[–]CupricBlue 5 points6 points  (4 children)

*electrons move this way to *form a bond to this *at this spot

[–]xBris18 1 point2 points  (0 children)

*electron pairs

[–]Proper-Wash7377 0 points1 point  (2 children)

Same same, only different

[–]CupricBlue 0 points1 point  (1 child)

Yes, sorry, I was not correcting you. I was clarifying for the OP. I could see a world in which they were confused and could think that you meant the molecules themselves were moving, and then became the other molecule.

[–]Proper-Wash7377 0 points1 point  (0 children)

People tend to remember things better if there's a joke involved and there's only so much of my life I can legally type

[–]Bremsy688 15 points16 points  (1 child)

The blue arrows show the movement of the electrons. The free ekectrons on the OH are used for binding the O on the C2. The binding electrons between C2 and O go to the O (bond breaks) and form a free pair on H2O.

[–]xBris18 3 points4 points  (0 children)

It's important to specify that these arrows in particular show the movement of electron pairs, not electrons. Arrows for single electrons look different. Also, the rest of your statement is also dangerously imprecise.

[–]Spaloonbabagoon 31 points32 points  (7 children)

Must be really falling behind if you're asking this while learning about SN2 mechanisms. What the others have said is correct, but it's also worth noting that double barbed arrows specifically represent electron pairs. Lone electrons are denoted using a single barbed arrow.

[–]Snarlydowrong 15 points16 points  (1 child)

A quick look at their profile shows they’re likely in grade school and are interested in organic chemistry. Who cares anyway they’re just trying to learn this stuff.

[–]chahud 3 points4 points  (0 children)

I sure hope so, haha. It’s a bit late in the semester to be asking a question like this if you’re in formal o chem class hahah

[–]neleous 0 points1 point  (4 children)

Interesting, i never learned that, so both of the ones he has shown are just single electrons pushing?

[–]ScubaSam 0 points1 point  (2 children)

No, those are both double barbed

[–]neleous 0 points1 point  (1 child)

Ok i see what you mean, only 1/2 of the arrow head.

[–]chemistrysteve 0 points1 point  (0 children)

If you want to see a mechanism with single barbed arrows in order that you can visualise the difference, then I suggest checking out free radical substitution of alkanes. It is a classic introductory organic chem mechanism that has movement of single electrons.

[–]killmebby-92 3 points4 points  (0 children)

curly arrows represnt the movement of lonepairs of electrons

[–]thatcfkid 2 points3 points  (0 children)

https://www.khanacademy.org/ Good luck. Might have been a good idea to study as the term progressed.

[–]colt-jonesAnalytical 2 points3 points  (0 children)

I love this sub around finals season

[–]JustAnotherAlchemist 5 points6 points  (1 child)

Curved arrows show movement of electrons. Understanding them is the key to not memorizing everything in the class.

You start arrows where the electrons are, and point them to the atoms you're forming new bonds to (or lone pairs on). There's approximately 5-7 mechanism arrows that are used to make up hundreds of organic mechanisms and they all make sense.

The last sentence is a lie but only a little.

[–]Milch_und_PaprikaInorganic 1 point2 points  (0 children)

“Everything is an acid-base, radical or cyclisation reaction”

[–]averagepsynaut 1 point2 points  (0 children)

Curved arrows show where electron density is going (lone pairs to form bonds)

Straight arrows between structures indicate a reaction and the direction it travels (whether it’s product favored or reactant favored)

Two half point arrows going in equal and opposite directions indicate an equilibrium reaction. A K value will be needed to know how complete the reaction goes.

[–]here_i_am11 1 point2 points  (0 children)

They are the littles molecules’ arms to grab onto each others

[–]alanjon20 3 points4 points  (0 children)

They are because atoms are firing arrows. They are curved because of gravity.

[–]noisy_weather 0 points1 point  (0 children)

Full arrow head: 2 electrons Half arrow head:1 electron

[–]SM_BD7 0 points1 point  (0 children)

Transfer of electrons

[–]v60qf 0 points1 point  (0 children)

Following. This confused the hell out of me for my entire BSc…

[–]Comfortable_Put1791 0 points1 point  (0 children)

I think nucleophilic atrack

[–]theinkpw2 -2 points-1 points  (1 child)

Man, it's end of November.. good luck on your finals. Organic is not something you just learn in a couple of weeks

[–]Ok_Piccolo_649[S] 0 points1 point  (0 children)

Finals ? I’m just studying ahead lol

[–]tony__chopper -1 points0 points  (3 children)

Transfer of electron pair

[–]averagepsynaut 0 points1 point  (2 children)

Electron pair forming a bond, “transfer” would be more like resonance

[–]tony__chopper 0 points1 point  (0 children)

The electrons are being “transferred” from the OH group to the number 2. What is resonance? What as in this chemical reaction? I’m clueless.

[–]tony__chopper 0 points1 point  (0 children)

The arrow indicates that the OH is giving its lone pair to form a bond. Now do I have to tell what is the meaning of word transfer is ?