The Periodic Table

« first day (1496 days earlier) ← previous day next day → last day (2892 days later) »

user116211

5:23 AM

We don't ask you to do our work, so please don't ask us to do your homework for you. — Jon Custer 14 hours ago

user116211

in The h Bar, 11 hours ago, by Chris White

^ New HW close reason

TIPS

7:57 AM

I really want to write some meta to procrastinate.

user116211

8:24 AM

Morning @TIPS

user116211

@TIPS what?

user116211

Hmm.

TIPS

@MAFIA36790 \o

It's been some time since I last wrote a post/

user116211

@TIPS what do you want to write on?

user116211

Let me guess: on @Mart, right? Like in memory of Lt. @Mart ......

user116211

8:28 AM

::sigh::

user116211

Sorry Mart for pinging you

TIPS

@MAFIA36790 Anything

3 hours later…

Dave

11:40 AM

So i just came out of my exam and i had a question which said boron isotope 10 and 11 exist in proportions of 19% and 81% what is the RMM of naturally occuring boron, drew a blank but took a guess, wondering if some one here could explain how to calculate it, and with luck hopefully its what i guessed!

Loong

Q: Calculating the average atomic mass of boron?

Boron has two isotopes with boron-10 and boron-11 having percentage abundance 19.6 % and 80.4%.How do i calculate the average atomic mass? i do know it that average atomic mass is calculated by multiplying the atomic massed of each isotope by fractional abundance and adding them. But i am stuck ...

user116211

!!greet/@Dave

Chemobot

Welcome to The Periodic Table @Dave! Here are our chat guidelines and it's recommended that you read them. If you want to turn Mathjax on, follow the instructions in this answer. Happy chatting!

Loong

Q: The formula for finding the percentage of isotopes in an element's atomic weight?

In my class my teacher showed us how to find it, with a method, but he didn't really state the formula. I conjured up a formula from what I observed and it works. Here it is: $$ \frac{i_1x + i_2y}{100} = A $$ $A$ = atomic mass $i_1$ = First's isotope's atomic weight $i_2$ = Second isotope's a...

periodic-table isotope

Dave

da hell thats identical to the exam question almost =/

but if you wanted to find the average mass of just naturally occuring boron which i assume is boron-10 ?

aren't those calculating all of it combined

Loong

11:47 AM

@Dave Your question says that natural boron constists of 19 % boron-10 and 81 % boron-11.

Dave

ah, well i got that wrong then :(

TIPS

12:14 PM

@Dave You have two data entries; 10 and 11. 10 is repeated 19 times and 11 is repeated 81. How would you calculate the mean?

10 times 19 and 11 times 81 divided by 100.

@Martin-マーチン What if we make "lacks minimal understanding" a close reason?

It used to be a CV on SO.

2 hours later…

TIPS

1:53 PM

Finally some action.

user116211

@TIPS Hmm, lacking research effort; I and many other reviewers at PSE cv such questions giving a customised comment. Although most of them fall under the domain of HW.

TIPS

@MAFIA36790 I'm talking about ones that don't.

Feeds meta.chemistry.se

Q: Is "Lack of Research" enough reason to close a question?

$\hspace{1cm}$As everyone who's spent a couple of minutes moderating Chem.SE knows, the bread and butter of the close reasons is homework. I really want to stop this, for reasons discussed and agreed upon before. $\hspace{1cm}$My biggest nitpick is with how the "homework" close reason is used to...

discussion close-reasons

user116211

@TIPS So, do you want an explicit reason for cv?

TIPS

I wanted to see if I do.

The third custom close reason slot is empty and that's annoying me.

user116211

2:04 PM

@TIPS That's a matter of debate quite long ago at the bar ;/

TIPS

@MAFIA36790 See? That's your biggest mistake. No one argues in a bar!

user116211

;_; h bar chat session.

TIPS

What about it?

user116211

hmm.

user116211

It's an evil rendezvous of agents of Hydra ;)))

TIPS

2:07 PM

That's why movies always shows a loony physician leading Earth to a doom.

Some of them take a step further and lead the galaxy to a doom.

WYSIWYG

2:39 PM

Guys please look at this post.

Q: Really understanding oncotic pressure and osmosis

I can't wrap my head around the idea of oncotic pressure and osmolarity, logically. I imagine a blood vessel. It is FILLED with proteins...Like a ton of proteins and solutes. So this means, according to oncotic pressure and osmolarity, that water will diffuse INTO this blood vessel. I can't und...