Symmetry elements and operations

A symmetry operation is an action of rotation or reflection or both that leaves an object in an orientation indistinguishable from the original one. A symmetry element is a line, a plane or a point in or through an object about which a symmetry operation is performed. There are 5 different types of symmetry elements, Identity given by the symbol E, Proper axis or Rotational axis of symmetry designated by Cn, Plane of symmetry or mirror plane designated by sigma, centre of symmetry or inversion centre given by i and improper axis or alternating axis of symmetry denoted by Sn. Different symmetry elements and their related operations have been discussed with appropriate examples.

[@niveoIe]

4 days from finals, 2 months of confusion solved from a 40 minute video. Thank you, bless you!

[@alkylpug]

Thank you so much for speaking slowly!! This is my first time learning about this topic and your relaxed pace of talking helps A LOT.

[@debbiehariette6335]

Fantastic video, clear, concise, made this subject much more understandable. Thank you, sir!

[@ChemWis]

Glad it was helpful!

[@amanuelyadessa3195]

Good 👍

[@listentome349]

Thank you! This helps me a lot to digest what I read in books.

[@ChemWis]

Glad it was helpful!

[@draftpunk6022]

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[@wisam3497]

Excellent presentation of the topic with examples everywhere, thank you much sir!

[@Vishwanshirajput]

Thank u so mach for sach a genius explanation
It's set on my mind

[@ChemWis]

Thanks for watching!

[@tammy0180]

The video makes me understand much more vs. reading the book. Thank you!

[@ChemWis]

Thanks for watching! I have also uploaded video on point group. There are many more videos related to different topics like stereochemistry, pericyclic reactions, name reactions, coordination chemistry. I have organized them in different folders in playlist of my channel. If you are interested in those topics you can go through them.

[@donn1297]

Thank u so much for your great videos! I was really losted in class, watching your vids make everything much more easier to understand !!:)

[@ChemWis]

You are so welcome!

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Thank you. I will recommend your video to my students.

[@Life_inHope]

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[@ChemWis]

Most welcome

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Outstanding video! Thank you so much!

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awesome video very helpful , thank you so much.

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love the way you are teaching

[@ChemWis]

Glad to hear that

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Mind blowing... explanation.....it makes my day.. Thanks

[@ChemWis]

It's my pleasure

[@khawarabbas6027]

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[@devarajuppuluri501]

Superb explanation

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[@ChemWis]

Thanks for your complements!

[@111loa4]

Very easy to understood .....

[@huynhvantram130]

it's very hopeful for me, thanks you.

[@ChemWis]

You're welcome 😊

[@chinthakawishwanath2062]

Clearly understand. Thank you

[@rahulsawant5616]

Nice video 🔥🔥

[@rodriguesissandemba6431]

Thanks Sir, but I have a question why which NH3 we can't get an axe of rotation that pass between the N-H liason?

[@manojkarki2527]

Nicely delivered. thank you

[@wendewows1743]

For the example at 14:58, I don't get why there are only 3 C2, why do you only cut between H1 and H2, H3 and H4, why not also between H2 and H3, H3 and H4, and H2 and H4.

[@rithik3871]

Cause when you cut through the other bonds you automatically cut through the alternative bonds too
For example H1 and H2 bond cuts through H3 and H4 bond
I hope it helps

[@humnasarmad5276]

Why benzene has 1 C6 axis although it has to rotate 6 time to have original configuration? It should have 6 C6 axis.?

[@TitanIMLS]

Sir, whats the name of the Program u use to draw?

[@FatieHA9811]

so clear explination ... thank you so much you helped me alot

[@ChemWis]

Glad it helped!

[@jojiekimara3362]

Thank You very much

[@JohnDoe-pk5ev]

at 14:21 how did you know it was gonna be C3(4 of them) passing through? Why not C2 ?

[@humnasarmad5276]

How do you know when and how to draw C2 or c3 axis on any structure?

[@warizoduola564]

Exactly, I have a problem getting that too
Do you know yet?

[@Adelegn-d7f]

How can we determine n?

[@eedibillisrivalli7345]

How are you saying whether that is C2 or C3

[@sprajasingh]

A molecule can have more than one symmetry axis, the one with the highest n is the principal axis. If a molecule has both C2 (180 rotation) and C3 (120 rotation) 360/n

[@liaqatshah4371]

So nice explaination thanks sir

[@111loa4]

Thank u for the information

[@Leezay-ue4rk]

Stil i can't understand it im gonna cry now thus symmetry js so messing up my mind plzz help 😢😢😢😢😢😢

[@kakandesimonsimon5895]

Understanding was not compulsory, not every movie we watch we understand them bro.this is inception

[@prshprsh5707]

thanks a lot sir..

[@Ayshaalshamsi-j1o]

thank you for saving my life

[@ChemWis]

Most welcome!

[@NuR-fv5by]

hum kyse jane,kishka 120° or kishka 180° hongi?

[@mannmoviereview]

But, how are you ginving names like C2, C3 C4? I mean on what baisi?

[@Maryam_Khalid_g6i]

On the basis of after how much rotation it gains the original orientation
For C2 = 360/2= 180
After 2 rotation of 180
It comes to original shape

[@shashikadilakshana1928]

Thank you ❤

[@ChemWis]

You're welcome 😊

[@jamunayadaw8161]

Thanks you so much sir for teach

[@himashalakmalhbm5744]

Thank u sir u explained very q

[@filiprc3030]

Great video !

[@ChemWis]

Thank you for watching!

[@younicekeepgoing9373]

Do you have pdf version of these slides so I can download and print it?

[@PritomAhad]

At 17:32, you said 5 C2 axis ? That means at five axis, 180 degree rotation will yield equivalent structure. Nd C4 means, 90 degree rotation will yield equivalent structure?

[@arumairajputhirasigamani2907]

yes

[@nursapaakbar7065]

Very informative, man.
Thnak you!

[@ChemWis]

My pleasure!

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I love you man

[@vishalmaurya-wx5cu]

Thank you sir

[@ChemWis]

Welcome

[@juwelhossain6643]

I need a video which define clearly motive and lattice,,,

[@mariyappillaiv5262]

Nice explanation sir
How to teach online class
Give tips

[@janfayeebojo9718]

Thank you sir😍

[@gipsonwahengbam7574]

thanks

[@theessentialist6813]

I searched in google and CH3CH3 does not have any sigma d mirror plane. minute 28:53 of the video. I DON'T UNDERSTAND.

[@ChemWis]

Eclipsed form of CH3CH3 has sigma plane while staggered does not

[@m4panda077]

nice bro

[@ChemWis]

Thanks

[@nikitasharma2962]

Abhi tak kanhi samjh ni aaya tha.. apse shuruaat ki mene MSC ki... Nice explanation... Can I have your number?

[@Maryam_Khalid_g6i]

Video should be 3D for such topics 😢

[@yayraagbo4946]

thank u very much sir

[@ChemWis]

Welcome!

[@111loa4]

Where u from

[@ChemWis]

Basically, I am from Mirzapur district, UP, India. Currently I am living in NOIDA.

[@celestepereira9601]

Nice one

[@ChemWis]

Thanks for watching

[@mohammadissa327]

Why ammonia don’t have a horizantal mirror(sigma h) ??

[@ChemWis]

Because of pyramidal structure of Ammonia

[@rashib4350]

fantastic!

[@ChemWis]

Thanks!

[@dayanaramli7079]

is it supposed to rotate it anticlockwise for Cn?

[@rafiqulislam-ej1qt]

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[@kadamanand304]

Sir please make a play list of ths make helpful

[@ChemWis]

I have already created the playlist

[@BACKAYDIGANS]

very good

[@ChemWis]

Thank you!

[@mamogirma3817]

Thanku sir

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[@111loa4]

Make the video a little bit faster

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[@martinman3073]

Sorry but how is it C2 for methane at 14:48

[@niveoIe]

in order to obtain the an orientation indistinguishable from the original upon rotation, the bottom two H that are on the same plane must be rotated by 180 in order to stay on the plane.

[@martinman3073]

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[@santoshnayak3586]

Thank You, Sir

[@rafiashoaib7758]

Aik strepsil hi kha leni thi🙄

[@mithu-kg7si]

🎉

[@JitendraSahu-bp3pp]

Please make a video cn point group

[@ChemWis]

I have made a separate video for symmetry point group in which I have discussed Cn point group. Please refer below link for the same.
ruclips.net/video/OFUAqVPv3k0/видео.html

[@channeld7166]

The rotation is quite confusing but thanks anyway

[@russelllane6058]

HELLO FRIENDS !!!!

[@draftpunk6022]

Sir plse provide this ppt 🙏🙏🙏

[@yavarnasrinivas]

Tq sir

[@ChemWis]

Welcome

[@amodkumar2712]

Sir
Most humbly and respectfully I have to State that I have some problems in group theory
1) what is reducible representation of cis butadiene
2) what is reducible representation of Trans butadiene
Kindly sir help me immediately on my email.

[@ChemWis]

I am giving you the hint. The irreducible representation for all the molecules belonging to a particular point group remains the same. Cis-butadiene belongs to C2V point group (which is the point group of water) and trans-butadiene belongs to C2h (which is the point group of trans -1,2-dichloroethylene). So, the irreducible representation of cis-butadiene will be the irreducible representation of water and irreducible representation of trans-butadiene will be the irreducible representation of trans -1,2-dichloroethylene or any molecule belonging to C2h point group.

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sir i didn't understand

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Ur speech too slow

[@kanhaiyamane4680]

Thank u sir

[@JitendraSahu-bp3pp]

Thanku sir