1

Chemistry / Re: Why does HNO3 exist but HPO3 does not?

« on: 29/11/2021 21:17:22 »

One can think of it as a hydration/dehydration equilibrium:
H₂O + HXO₃ H₃XO₄

There are two reasons that the equilibrium favors the left-hand side when X = N, but the right-hand side when X = P, As, (or Sb, I believe):

1) (the simple answer, pointed out by Bored chemist) nitrogen is the smallest of the bunch (covalent radius of N = 75 pm, P = 106 pm, and As = 119 pm), so it is simply harder to fit the extra oxygen on there.

2) (the complex answer) the 2p orbitals on nitrogen and oxygen have fairly similar energies** (–13.1 and –15.9 eV vs vacuum, respectively) as well as very similar sizes (as noted in point 1), as well as shorter σ bonds (also due to point 1). This means that the p orbitals on neighboring O and N atoms can form very strong π interactions, and that the electrons in the π bonding and π anti-bonding orbitals would both be shared fairly equally.

In contrast, the valence of the phosphorus atom is a 3p orbital, with a much higher energy** (–10.2 eV; again comparing to –15.9 eV for O), and extends much farther away from the nucleus (but not towards a neighboring atom).

Screen Shot 2021-11-29 at 4.15.13 PM.png (42.56 kB . 794x624 - viewed 7327 times)

This means that in HNO₃ the nitrogen atom has much more electron density compared to the P atom in HPO₃ (the N is less electrophilic than the P, making the N less likely to accept electron density from another O), while the oxygen atoms bound to N have less electron density than those bound to P (the P-bound O atoms are more basic than N-bound, making them more likely to gain H⁺) and much stronger N=O bonds than P=O bonds (so it is easier to break the double bonds).


Screen Shot 2021-11-29 at 8.08.24 PM.png (45.63 kB . 546x680 - viewed 7302 times)

* https://www.schoolmykids.com/learn/interactive-periodic-table/covalent-radius-of-all-the-elements
** https://www.colby.edu/chemistry/PChem/notes/AOIE.pdf

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Chemistry / Re: Why does HNO3 exist but HPO3 does not?

« on: 26/11/2021 12:14:23 »

Arsenic and antimonic acids are typically of the type H3XO4 (Though the meta versions exist).
So the question is why doesn't nitrogen usually follow the rules?
And the answer is largely that it's small.
Though Na3NO4 etc do exist
https://en.wikipedia.org/wiki/Orthonitrate
So it seems they all follow both sets of rules.

3

Chemistry / Re: Why does HNO3 exist but HPO3 does not?

« on: 26/11/2021 11:12:03 »

https://pubchem.ncbi.nlm.nih.gov/compound/Metaphosphoric-acid

tells you how to make it and what it is used for. Interestingly it causes skin burns and eye damage, and its principal use is in cosmetics!

4

Technology / Re: Do operating system updates require new computers?

« on: 19/11/2021 05:44:33 »

Do operating system updates require new computers?

Yes and No.

The new operating system will have new features that consume more RAM, CPU power and disk space than the old operating system.
- Microsoft would have tested the new operating system on new computers with the latest multi-core CPUs, large amounts of RAM and large hard disks - and it works fine.
- But if you have a 6 year-old computer with low-powered CPU and limited RAM, you will find the old operating system is noticeably faster than the new one; and that many of the new features are unusably slow. So there is no point in upgrading to the new operating system on an old computer.

At some point in time, Microsoft will cease supporting the old operating system with bug fixes and security updates, so you will be forced to buy a new computer, which will come pre-loaded with the new operating system.

5

Question of the Week / Re: QotW - 19.02.18 - Why does alcohol make you drunk?

« on: 18/02/2019 18:50:35 »

As far as I know, the exact mechanisms of alcohol intoxication are not known. However, it appears that the primary effects are related to potentiation of GABA pathways in the brain (so many of the effects are similar to those of benzodiazepines, GHB/GBL, gabapentin, and barbiturates, each of which potentiates or activates this pathway in different ways.)

Unlike these other drugs, especially benzos, which are quite potent and selective (a 2 mg dose of valium wouldn't be unusual), alcohol is very weak and unselective--requiring doses typically measured in ounces or deciliters!

As I understand it, activating GABA pathways dampens other signals in the brain--with the effects manifesting more strongly for processes that require more neurons (especially if thee neurons are in different parts of the brain). This means that just a little bit of alcohol can potentiate the GABA pathways a little bit, causing the most change in higher cognitive functions like reasoning and self-control. As the dosage increases, the effects there increase, and it also starts manifesting in fine motor control and response time. When really large doses are reached, even the ability to breath can be compromised.

Acute toxicity of alcohol (for a single large dose) can largely be attributed to loss of the ability to regulate breathing, or aspiration of vomit. But most injuries and deaths due to acute alcohol intoxication are due to loss of gross motor skills and response time, especially when it comes to things like automobiles and stairs...

However, much of the harm from alcohol is not from acute, but rather chronic abuse. Because the dosage is so high, alcohol is very hard on the liver and kidneys. Also, the neural pathways that alcohol acts on become resistant, then accustomed to and then dependent on the alcohol. Those who drink excessively for a long time can suffer from the potentially fatal DTs (delerium tremens), which can cause hallucinations and seizures (both of which can be treated with some of the GABA potentiators mentioned earlier).

6

New Theories / Re: Pest control

« on: 22/12/2018 17:02:08 »

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It would appear that you are just a lousy, bloodsucking spammer trying to put the bite on us.
Well, we have our own method of pest control. Patented ‘Spammoff’ (sound of spray can )

7

Physiology & Medicine / Re: What processes produce and mitigate reactive oxygen species?

« on: 26/10/2018 22:41:40 »

We have a policy of not doing homework assignments for people. You have to think a little bit.

But you can get some starting points here:
https://en.wikipedia.org/wiki/DNA_damage_(naturally_occurring)#Types

8

General Science / Re: What do nerves do in a human?

« on: 02/09/2018 09:58:15 »

This video we made about how nerves work might be helpful:

9

Just Chat! / The Poem!

« on: 09/08/2018 02:05:00 »

Considering a " Roses are Red " poem consists of 4 rhyming lines...

Simple Instructions :-
1)Each member can type/post only one(1) line consisting of not more than 100 to 120 characters.
2)Once you post your line then you wait your turn for at least three(3) other members to post their lines.
3)If two(2) members post a line simultaneously, the same day n same time then the ' first come first served ' rule applies and the other member should ideally delete or modify their post.
Please make sure OUR lines RHYME!

Inspired from the ' Science " roses are red " poems ' OP by Tomassci.
It was a pleasant surprise to notice we have poets in the house.
(This could also serve as an experiment of how well a diversified group of like minded people irrespective of their difference of opinions can synchronize their actions by following a simple set of instructions and come together in an orchestrated manner to create something fun, interesting and possibly beautiful.)

Like a hive mind, where there are no leaders & no followers.
Working towards a common goal but still retaining respective individualities.

P.S. - if u are a Guest n like/enjoy The Poem! then no one is stopping u from joining in & being a part of it, except for your ownself.
🌈

10

Geek Speak / Re: Do you know mobile app for photo editing, if possible, similiar to GIMP?

« on: 04/08/2018 23:20:42 »

There's pixelr, which I've used a few times and seems pretty user friendly.

11

Guest Book / Re: Introduce yourself and say hi.

« on: 03/08/2018 11:59:11 »

The only rules we have are those contained in our forum acceptable usage policy https://www.thenakedscientists.com/forum/index.php?topic=8535.msg99452#msg99452

Some key points:
we cannot, amongst other things, host material that is obscene, that constitutes harassment,  that promotes terrorism, that is racist, or that constitutes a breach of copyright.

Keep it family friendly, all ages view here

Be safe, we advise no personal data

No spam. That includes promoting your own business or pet theories:
- The site is not for the promotion of business interests, or other personal ventures.  The only exception to this is where the advertisement is supplied by the owners of the forum to further their own business interests.
-The site is not for evangelising your own pet theory.  It is perfectly acceptable that you should post your own theory up for discussion, but if all you want to do is promote your own idea and are not inviting critical debate about it, then that will not be acceptable.
- It is not acceptable simply to post material onto this forum that you have posted elsewhere, except where the post is specifically pertinent to an ongoing thread.  If you start a thread with a post that is for all practical purposes the same as you have posted elsewhere, we will generally assume that you are evangelising, and will act accordingly.

12

Just Chat! / Re: Science "roses are red" poems

« on: 01/08/2018 07:02:10 »

All Roses aren't Red
The Sky isn't always Blue
The Universe ain't just all E = mc²
It's got Laughter & Giggles too


Screenshot_20180801-112840.png (257.69 kB . 600x1024 - viewed 25946 times)

Image Source/Copyrights Credits & Thanks - FunnyAnd.com

13

Just Chat! / Re: how i was cured from cancer using Cannabis oil

« on: 16/07/2018 08:43:24 »

If cannabis oil is legit in fighting/curing cancer, then why don't "big pharma" distill the active, cardigan ingredient in cannabis (whatever it is) and turn into a medicine? It would be very profitable.

14

General Science / Re: How does temperature affect the colour of metals?

« on: 02/07/2018 11:43:28 »

Part of the color change is black-body radiation - as an object gets hotter, it tends to emit more energy at higher frequencies, so a yellow glowing piece of metal is hotter than the same piece of metal glowing a dull red.
But this color change goes away after the metal cools down.
See: https://en.wikipedia.org/wiki/Red_heat

Part of the color change is chemical. At higher temperatures, chemical reactions like oxidation (or "rusting") to occur much more quickly. Heating steel wool in a flame can can quickly produce a discolored layer of rust on the surface.
This color change remains after the metal cools down.

Titanium naturally forms a thin, clear protective oxide layer that inhibits further oxidation.

However, under that protective layer, titanium is still a very reactive metal - it is even able to react with nitrogen at high temperatures; we normally consider nitrogen to be a fairly inert gas.

Maybe the color change you see is the reaction product with some other substance at high temperatures?
See: https://en.wikipedia.org/wiki/Titanium#Chemical_properties

15

General Science / Re: Can you help me with my homemade Teleportation project?

« on: 20/06/2018 22:35:59 »

Hello,PointofNoReturn. I'm very interested in partnering you on this exciting project. The best way to proceed would be for you to teleport directly to my sitting room. A cold beer and sandwiches are waiting your arrival.

16

Physiology & Medicine / Re: Does thinking use water?

« on: 07/06/2018 12:12:18 »

Does thinking use water?

Working hard on a treadmill consumes more energy in your leg muscles and loses water as sweat.

But you don't consume noticeably more energy or water whether you are sitting doing maths problems or sitting and daydreaming. In both cases, your breath will contain a similar amount of water vapor, and your kidneys will filter the same amount of blood and produce the same amount of urine.

Whenever I'm thinking hard at work I find myself ridiculously thirsty

If you lose track of the time you could go too long without a drink, and your body reminds you by triggering the thirst response.

On the other hand, if you are borderline diabetic, and you sip your favorite sugary cola drink, that will cause an intense thirst.
https://en.wikipedia.org/wiki/Diabetes_mellitus_type_2
 

when I'm dehydrated I feel like I can't solve problems as well.

Your body does need a good salt/water balance to function correctly - and you will get a strong thirst before it gets too far out of balance.

If you have a thirst, your body will be distracting you away from your maths problems.

17

General Science / Re: The sounds of science...

« on: 02/06/2018 10:33:25 »

Great idea for a thread - well done for starting it!

18

Physics, Astronomy & Cosmology / Re: Do see-through metals exist?

« on: 29/05/2018 12:04:15 »

Why are some things (i.e. glass & a few plastics) see-through?

There are a few reasons why you may not be able to see through some material, for example:
- It may be reflective, a common characteristic of metals. The free electrons in a metal move to oppose an incoming light wave, bouncing it off at the same angle that it arrived. On the other hand, insulating materials (like most plastics) have no free electrons, so the light penetrates the surface.
- It may have a high index of refraction (like diamond), or a moderate index of refraction (like glass). This makes a fraction of the light reflect from the air-material boundary, and more reflect from the far side too. This is partially reflective.
- It may scatter the light, like snow, a jar of sugar crystals, or clouds. In this case, the light gets through, but its path has been bent so many times that it doesn't form a clear image.
- It may absorb the light at all frequencies, like graphite in a pencil.
- It may absorb some colors but not others, like a dye or pigment.
...and there are other combinations too

Something that we consider quite transparent (like window glass) is not totally transparent - if you see someone carrying a sheet of glass, you will see that the edges look very green - that is because not  much light makes it all the way through a meter of more of glass from one side to the far side.
See: https://en.wikipedia.org/wiki/Opacity_(optics)

Would it be possible, for example, to make a see-through metal?

If you extend the definition of "see-through" to all electromagnetic radiation, that opens up a few more possibilities:
- Silicon is a semiconductor (partway between a metal and a non-metal), so it looks metallic and shiny. However, it is quite transparent at infra-red wavelengths.
- X-Rays are absorbed when they strike the inner electrons of heavy metals like lead or gold, close to the very positive nucleus. Light elements like carbon, hydrogen, oxygen and nitrogen (as in human flesh) don't have a highly charged nucleus, so their electrons don't absorb X-Rays so well. That is why bones (containing the slightly heavier metal calcium) tend to show up clearer, while the skin, organs and muscles are fairly transparent.
- Low-frequency radio waves penetrate a short depth into a metal surface, defined by the penetration depth. The penetration depth is greater for low frequencies, and with poorer conductivity metals. So a certain fraction of low-frequency radio waves will pass through a poor conductor like lead.
See: https://en.wikipedia.org/wiki/Penetration_depth

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Question of the Week / Re: QotW - 18.05.21 - Could we eat an alien?

« on: 22/05/2018 00:34:23 »

That depends on how similar we are to them. They would need to be sufficiently similar to us biochemically in order for our enzymes to break down whatever their tissues are made of. Even being carbon-based wouldn't be enough of a guarantee. They might, for example, be composed of molecules that are the chiral mirror of our own. Our enzymes would have trouble with those.

20

Physiology & Medicine / Re: Diet and Weight Loss | The best diet plan and natural ways of weight loss

« on: 11/05/2018 13:49:50 »

It would be convenient and help to freshen
If you simply asked a forum question
Are ewe here by chance to stealth ?
A sneaky spam about wealthy health ?