The Periodic Table

getafix

06:13

also, @orthocresol omg I am so sorry i thought i replied to you. But good to know you're doing well, the synthesis syndrome aside (a feeling I know all too well).. :)

gateprep

09:09

(Miller indices,Structure of diamond,graphite)

which book to follow

@Martin-マーチン

Martin - マーチン

09:29

Please don't ping me with questions like these. I'm pretty sure there is something about crystal structures in the resources post...

Secret

10:05

Progress Report: Succesful Sodium Production with Inexpensive Chemicals and Continuing Optimizations

►

I never expected that one can get pure sodium with alcohols

I guess we the chemistry community need to chat more with the amateur chemists

getafix

10:23

@Secret NurdRage is not an amateur chemist. He has or is working towards a PhD in Chemistry, iirc.

Secret

O I see...

orthocresol

13:19

If anybody here is starring entire conversations for no apparent reason, please stop.

orthocresol

13:49

That's a new one...

ffahim

14:21

Hey everyone

According to quantization it's said that emitted or absorbed energy is quantized. So when it's said in bohr's model an electron changes its orbit. Let's say the energy difference is 100kj, now, according to quantization is the 100kj itself a quantum. Or the 100kj will be absorbed in quantized way?

pentavalentcarbon

14:34

@ffahim Quantization refers to the energy levels. The 100 kJ would be absorbed in a quantized way, assuming that it matches one of the energy gaps or allowed transitions of the system.

ffahim

15:05

@pentavalentcarbon fine. As 100kj will be absorbed in a quantized way. Then it has to be n multiple of 1 quanta or photon. What would be the energy of this photon. Of whose n times =100kj

pentavalentcarbon

15:52

@ffahim You can't know what it is unless you know the energy level spacing, which depends on the model. You also need one of either the initial or final energy levels, so you can solve for what the other one is.

ffahim

OK listen. Let's say the energy of n=3 is 200kj,

Energy of n=4 is 300 kj

So to jump to the 4th shell from 3rd the required energy is 100kj , if this 100kj is absorbed by quantization. By n multiple a photon E=hv whose n multiple =nhv=100kj, how do we get the energy of photon here @pentavalentcarbon

@pentavalentcarbon just tell me Pls whether quantization is related to Bohr's model or not. If so how Pls elaborate

pentavalentcarbon

Quantization appears everywhere in quantum mechanics, including Bohr's model. That's one of the underlying postulates of quantum mechanics.

You can't know how many photons that is unless you know the frequency or wavelength of a single photon.

I'm also ignoring the fact that I don't think a single photon has 100 kJ of energy.

ffahim

16:07

What is quantized energy actually?

The energy absorbtion or emission will always be an integer multiple of a quantized energy according to Plancks quantum theory

pentavalentcarbon

I was going to mention this earlier. From one point of view all of energy is quantized, since it's a finite number...say 100 kJ. But that doesn't really matter. When we talk about quantization, we really are talking about the interaction of energy with energy levels that have discrete spacing.

So don't confuse energy with energy levels.

ffahim

Different Energy levels have different energies. So there are energy differences required to go from one energy level to another. Right?

pentavalentcarbon

@ffahim I understand what you're saying, and I think you understand it too, but it's better to say just "an integer multiple", which then leads to absorbing or emitting a specific amount of energy. It's because of the energy levels of the system.

Yes, that's correct.

I'm being a little pedantic.

ffahim

OK do you mean to say even though we know the energy difference between two levels is 100kj we don't know the energy of the photon in this case

Rishi Kakkar

cu2+to cu or mn2+ to mn which Is easier to reduce

ffahim

16:14

@pentavalentcarbon

pentavalentcarbon

@ffahim We almost never talk about absorbing or emitting multiple photons simultaneously for these problems. But, if you know there has to be more than one photon, you can't say how many unless you know it's wavelength or frequency, because there are multiple unknowns in $E = n h \nu$.

ffahim

E=nhv

E=100KJ

pentavalentcarbon

But if you don't know v, you can't solve for n.

ffahim

Ok I think I got it, I should always keep in mind that the 100kj energy will be absorbed be n numbers of photon?? @pentavalentcarbon

But to get the energy of that photon I need to know it's frequency?

pentavalentcarbon

Exactly.

ffahim

16:20

If that's the case why in our textbook just divided the energy 100kj by plank's constant to get the value of the frequency. Is that theoretically correct?

They didn't bring the concept of Quantization. Rather they just simply used E=hv

pentavalentcarbon

Yes, it's correct, because it assumes that n = 1. Quantization is still present: that's the energy of a single photon.

ffahim

I know they assumed n=1, but is that even correct to assume. Does that support in practical cases

pentavalentcarbon

Actually, yes. Most common experiments only involve the absorption or emission of a single photon.

And for such simple models as the Bohr model, particle in a box, and others, that's a much larger assumption than saying there's only one photon involved.

ffahim

I see thanks a lot. Another little help. What quantization has to do with spectrum having black lines

pentavalentcarbon

That's an absorption spectrum, right?

ffahim

16:25

Yeh

pentavalentcarbon

Well, you know that the transition between energy levels is quantized, and there are only so many low-energy transitions. You only absorb photons at those specific energies.

Those specific transition or absorption energies appear as black lines on an absorption spectrum.

ffahim

When energy is being transmitted will I see rainbow or a specific color (where only one orbit change is found)

pentavalentcarbon

Yes, exactly. Specific colors, with the number of lines being directly related to how many ways you can emit a photon.

ffahim

The black lines refer that those energies have been absorbed? Or emitted?

pentavalentcarbon

In an emission spectrum, black lines are where photons aren't emitted. In an absorption spectrum, black lines are where photons are absorbed. It depends.

ffahim

16:33

OK thanks a lot

:)

pentavalentcarbon

Good luck!

M.A.R. ಠ_ಠ

18:47

@gateprep Hi! Well, I'd be the culprit of saying you can ask whatever you want, but please stop. This is getting really annoying. Even asking in a public informal chatroom has etiquette, and you're not doing very well with that. Please don't ping any more people in the future.

4

Jeez autocorrect, what if I didn't notice it?

@gateprep I recommend you take a look at how @ffahim formulated and asked his question right up there, and how he got helped.

@RishiKakkar have you reached the electrochemical series section in your textbook? If you haven't, take a look at chemguide.co.uk/physical/redoxeqia/ecs.html and thy answer shall descend upon thee

Rishi Kakkar

19:13

well how to study organic chemistry

@M.A.R.ಠ_ಠ

from starting

M.A.R. ಠ_ಠ

@RishiKakkar step one: open a magical real life pdf called book

Rishi Kakkar

I mean which one

well sonnet 1 is itself it is too much

M.A.R. ಠ_ಠ

5

Q: Resources for learning Chemistry

Based on various other Stack exchange site (Mandarin Chinese, Russian and German), we adapt this project here for chemistry, since it's a great idea to have all kinds of resources in one place. This is a specifically created Community Wiki which gathers resources for learning Chemistry. The list...

See if something catches your eye . . .

Clayden . . . Solomon--Fryhle . . . March

All kinds of available flavors . . . Er, authors

Different levels

Rishi Kakkar

Peter Sykes??

I have Clayden but is too much high for me

@M.A.R.ಠ_ಠ what would u suggest

M.A.R. ಠ_ಠ

@RishiKakkar Have you heard of Morrison--Boyd's?

Rishi Kakkar

19:25

no I am new to it

it》 organic chemistry

M.A.R. ಠ_ಠ

Good introductory book

Rishi Kakkar

ok and what should I aim to understand

the mechanism

or the application

or reagents

M.A.R. ಠ_ಠ

A little bit of all of them

Rishi Kakkar

why ??

M.A.R. ಠ_ಠ

1. They're really interconnected

2. You would probably be examined with all of them

Rishi Kakkar

19:30

you know there is always a third reason but fine two are enough

M.A.R. ಠ_ಠ

I mean, I have no idea how you can get good at reaction mechanism without knowing what reagents or catalysts to use

@RishiKakkar 3. ???

Rishi Kakkar

I.mean it's most of the humans nature to provide 3 or 5 reasons

for anything @M.A.R.ಠ_ಠ

M.A.R. ಠ_ಠ

3. I am a very handsome person and you should listen to whatever I say

4. My avatar is cooler than yours

Rishi Kakkar

thats illogical to the subject but I can't see your face but I can listen to you

M.A.R. ಠ_ಠ

I actually can't see your avatar

But it can't be cooler than mine

Rishi Kakkar

19:34

but someday I will make it

ok so what are working on or u are all set

read the chemistry for 20 or so years

M.A.R. ಠ_ಠ

@RishiKakkar What

Rishi Kakkar

read(it's third form )

I mean what are doing in chemistry

I mean studying ??

M.A.R. ಠ_ಠ

What are who doing in chemistry? O.o

Rishi Kakkar

I meant u after are and before doing

M.A.R. ಠ_ಠ

Well, I've been in this site for quite some years, and I'm having fun

Rishi Kakkar

19:39

and as per studies

M.A.R. ಠ_ಠ

I actually probably relatively know more biology than chem, because of our bizarre education

Rishi Kakkar

:)

biochemistry

M.A.R. ಠ_ಠ

Whoa don't use the B-word

Rishi Kakkar

ok like I didn't say b for bitch or something ??

M.A.R. ಠ_ಠ

Biochemistry is more vulgar

Rishi Kakkar

19:42

why so ??

my father is a good one

M.A.R. ಠ_ಠ

Dude, I'm not gonna explain my lame joke

Biochemistry is basically memorizing 80 enzymes each doing 80 jobs

Very odd economy

Rishi Kakkar

ohh my messed up man

no doubt he is such a sharp memory

well as per can u tell me why nitrogen single bond is weaker then phosphorus single bond

nd is weaker then phosphorus single bond

M.A.R. ಠ_ಠ

@RishiKakkar you mean N-N vs. P-P?

Crap, low battery

Hexacoordinate-C

22:04

@RishiKakkar On the table I have $\Delta H_f(298K, \ce{N-N}) = 945 kJ/mol$ and $\Delta H_f(298K, \ce{P-P}) = 490 kJ/mol$. Which makes sence knowing their elecronic properties.

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