Subject: Can someone please explain?
Posted by: Mixamatosis
Date: Jan 21 17
I've read that it's dangerous to mix ammonia and bleach. Variously I've read that it can produce deadly cyanide gas, chlorine gas (which is said to be bad for you) and even explosions.
However swimming pools are kept fit for use with chlorine, and our urine contains ammonia but then we may clean toilets with bleach. Also many cleaning products contain either ammonia or bleach and it would be easy to use them unthinkingly in combination.
How is it that people aren't generally harmed by these dangers when swimming in swimming pools or doing daily cleaning, or are we being harmed at low level and is the harm cumulative?
Posted by: Mixamatosis
Date: Jan 21 17
I've read that it's dangerous to mix ammonia and bleach. Variously I've read that it can produce deadly cyanide gas, chlorine gas (which is said to be bad for you) and even explosions.
However swimming pools are kept fit for use with chlorine, and our urine contains ammonia but then we may clean toilets with bleach. Also many cleaning products contain either ammonia or bleach and it would be easy to use them unthinkingly in combination.
How is it that people aren't generally harmed by these dangers when swimming in swimming pools or doing daily cleaning, or are we being harmed at low level and is the harm cumulative?
526 replies. On page 2 of 27 pages. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
brm50diboll 
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So what exactly is a quark, Brian? Reply #21. Feb 10 17, 11:10 PM |
| brm50diboll
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I'm so glad you asked, Brian. In grade school we learned atoms were made of protons, neutrons, and electrons. Electrons are very lightweight particles in a family called leptons. But protons and neutrons, which are much heavier than electrons and are found in the nucleus (which electrons are not) are I a different family called baryons, which itself is a subfamily of an even larger group called hadrons. All the other members of the baryon and hadron families are extremely unstable and decay very rapidly, but they, like common protons and neutrons, are composed of even smaller particles called quarks. Electrons, which belong to the lepton family, are not composed of quarks. Quarks come with fractional charges. Baryons like protons and neutrons are always composed of three quarks. Other hadrons called mesons are composed of quark-antiquark pairs, but quarks are not found alone. Quarks are bound to other quarks inside hadrons by the strong nuclear force carried by gluons. There are six main varieties of quarks are called up, down, strange, charm, bottom, and top. Up and down are "garden-variety" quarks. The other four types are very exotic, rare, and unstable. The up quark has a charge of positive two-thirds. The down quark has a charge of negative one-third. A proton contains two up quarks and one down quark, which adds up to a net charge of +1. A neutron contains two down quarks and one up quark, which adds up to a net charge of 0, just like we were taught in grade school. The strong nuclear force, in addition to holding quarks together inside hadrons like protons and neutrons, also holds the nucleus itself together, overcoming the electric repulsion between all the positively charged protons. Other exotic and unstable hadrons exist composed of other quark combinations. For example, three down quarks would be a particle with a charge of -1 (not an electron, though, a very unstable hadron which would rapidly decay in a fraction of a second.) These other exotic hadrons all have names, but I would have to look them up. Atom smashers can create exotic quarks and exotic hadrons, and identify them as they decay. Reply #22. Feb 10 17, 11:29 PM |
Mixamatosis
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Interesting but a bit like absorbing a complicated plot in a classic novel - all these families and pairs with different names. I'm not sure all of this had been discovered when I was at school. I don't remember being taught any of it. Reply #23. Feb 11 17, 5:42 AM |
| brm50diboll
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Just the part about protons, neutrons, and electrons being the parts of an atom. Everyone should know that. Quarks are definitely not taught in grade school. They were first hypothesized in the 1960s, and subsequently have been discovered and their properties determined as the years have gone by. Reply #24. Feb 11 17, 12:36 PM |
| brm50diboll
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Standard grade school science curriculum in the US has for many years (including when I was a kid) taught the following: Atoms are composed of three types of particles, protons, neutrons, and electrons. Electrons are light and negatively charged and are outside the nucleus. Protons and neutrons are much heavier than electrons and found together in a very tiny center of the atom called the nucleus. Protons are positively charged, neutrons are neutral. All of the preceding is taught (I can't say how well or what percentage of the adult population remembers it, but it has been taught) since at least the 1950s, maybe even the 1940s. Reply #25. Feb 11 17, 12:44 PM |
jabb5076
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That's about what I remember from HS science in the late 1960s-early 1970s. At University I only had to take biological science so escaped quarks, et al. Reply #26. Feb 11 17, 4:45 PM |
| brm50diboll
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Yeah, nobody really *needs* to know about quarks (except maybe the physicists), but it's a legitimate FT category as far as I'm concerned, just as Manga is, except I happen to know a little about quarks, and nothing about Manga. Reply #27. Feb 11 17, 5:38 PM |
| Mixamatosis
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Something's coming back to me now. I must have been taught something about protons, neutrons and electrons, because I did know that protons were positively charged, electrons negatively charged and that neutrons were neutral. It's great what the fun trivia quiz site brings back to mind. The only science I kept up after age 14 was Human Biology. Sadly my maths and music books were destroyed following a house clearance at which I was not present. I would like to refer back to them now to remind myself of forgotten stuff. They teach maths differently these days so the text books are different from my schooldays. I've forgotten the rules of algebra, and some geometry (geometric theorems). Reply #28. Feb 12 17, 4:31 AM |
| Mixamatosis
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My science books also did not survive except for one very basic one. My sister had saved them to her attic but I didn't know she had them. At some stage she offered the survivors back to me but the non-survivors had been eaten by mice and were in poor condition, so she'd thrown them out. Reply #29. Feb 12 17, 4:33 AM |
| brm50diboll
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So Brian, what is this magnitude scale in astronomy I hear about? Reply #30. Mar 02 17, 9:38 PM |
| brm50diboll
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Very complicated, but bear with me. The apparent magnitude scale is a reverse logarithmic scale of star brightness. Reverse means the magnitude is lower (not higher) as the star gets brighter. Logarithmic means each increment corresponds to an approximate 2.5 factor in brightness (actually the factor is the fifth root of 100, or 2.52... but I digress.) So a star of magnitude +1.0 is about 2.5 times as bright as a star of magnitude +2.0, and a star of magnitude 0.0 is about 2.5 times as bright as a star of magnitude +1.0, which is 2.5×2.5 or about 6.3 times as bright as a star of magnitude +2.0. Magnitudes can actually be negative (which is very bright, by the way). The brightest star in the night sky, Sirius, checks in at magnitude -1.46. Some planets are even brighter than Sirius. Mars and Jupiter reach maximum brightness at -2.9, but Venus is at maximum brightness at -4.7. On this scale, a full moon is about -13, and the Sun is at -27. For positive magnitudes, the larger the number, the dimmer the star. People with average vision on dark, cloudless, moonless nights can see stars down to about +6.0 on this scale. There are only a few thousand stars visible to the naked eye. With binoculars, the visible magnitude range can be extended down to about +9.0, and with a small home telescope, about +12.0. Since Pluto checks in at +14.0, it cannot be seen with small home telescopes. Polaris, the North Star, is NOT the brightest star contrary to a common misconception (and the Gerry Rafferty song "Right Down the Line".) I've already pointed out Sirius is the brightest star in the night sky. Polaris actually ranks #49 of bright stars at a mere +2.0. Polaris is famous for its position, not its brightness. The top five brightest stars are Sirius (-1.46), Canopus (-0.7), Alpha Centauri (-0.3), Arcturus (-0.1), and Vega (0.0). Canopus and Alpha Centauri, despite their brightness, may be unfamiliar to many because they are southern hemisphere stars. I can barely see Canopus just above the southern horizon this time of year from Longview TX, but I can't see Alpha Centauri at all from Longview. These Southern stars are best observed from the Southern Hemisphere. In addition to apparent magnitude, which I've just discussed, there is also a quantity called absolute magnitude, but that is a different animal altogether. Maybe some other time. Reply #31. Mar 02 17, 9:59 PM |
| Mixamatosis
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This is hard to stick in the brain because magnitude means size or scale doesn't it and largeness at that, so a negative magnitude being brighter than a positive magnitude is counter-intuitive. No wonder people have a hard time with science. You just have to remember stuff that doesn't seem logical at times. Reply #32. Mar 04 17, 3:47 AM |
| brm50diboll
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The reason it is this way is actually historical. Long before the visual magnitude scale became thoroughly mathematical and quantitative, it was used qualitatively. The ancient Greeks called the brightest stars they saw "first magnitude", the next group "second magnitude", then "third magnitude", and so on all the way down to the dimmest stars they could see, which were called "sixth magnitude". Decimal values were not used, nor negative ones, because the scale was qualitative. So by this method, Sirius was "first magnitude". When it became possible to quantitatively measure star brightness precisely in the early 20th century, the existing scale was converted to a quantitative scale. Since brighter stars were lower magnitudes than dimmer stars, the scale became reverse logarithmic to be consistent with the existing qualitative scale. A representative "average" first magnitude star (definitely not Sirius) was assigned magnitude +1.0. A representative "average" sixth magnitude star (barely visible under good conditions to be seen by the naked eye) was assigned magnitude +6.0. It was observed that the prototype +1.0 star was 100 times as bright as the prototype +6.0 star, and, since the magnitude difference was 5, (6-1=5), the required factor for the reverse logarithmic scale therefore became the fifth root of 100, or 2.52.... Now the new scale was quantitative but still consistent (roughly) with the old one, but much more accurate, and extended to decimal values, negative values, and values greater than 6, indicating stars too dim to be seen by the naked eye. Whenever something counterintuitive exists, there is probably a logical historical reason for it, and that is the case for the apparent magnitude scale as it exists today. Reply #33. Mar 04 17, 5:39 PM |
| Mixamatosis
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That explains it. So much to learn, and just as I have the time to learn sadly the brain capacity is diminishing, but not too quickly I hope. Reply #34. Mar 04 17, 6:18 PM |
Mommakat
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LOL....I know the feeling Mixie Reply #35. Mar 04 17, 6:26 PM |
| brm50diboll
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So Brian, why do you ask yourself questions on this thread and then answer them yourself? You must know that is very strange. Are you crazy? Reply #36. Mar 15 17, 12:44 PM |
| brm50diboll
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Not really. (But who am I to judge myself, actually?) I do this because I find the Sci/Tech boards useful but extremely underutilized. I want to encourage people to ask questions, but if none are asked, I will ask (and answer) a few myself just to keep this thread relatively recent. Thank you for asking, Brian. Reply #37. Mar 15 17, 12:47 PM |
| Mixamatosis
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I was reading yesterday that there's a risk associated with some prescribed skin creams used for conditions such as eczema and psoriasis. Some contain paraffin which can build up in clothes and bedclothes and there are some reported cases of people accidentally setting themselves alight (mainly through smoking) because paraffin acts as an accelerant http://www.bbc.co.uk/news/uk-39308748 It got me thinking about cases of "spontaneous combustion" reported in Victorian times and even featured in a Dickens story ("Bleak House"). I was wondering whether the explanation could lie in some of the occupations people had then and the chemicals they might come into contact with during their occupation (e.g. coal, paraffin etc). Also Victorians smoked and often didn't wash as often, not having bathrooms) so could that be the explanation for the cases of spontaneous combustion - a build up of inflammable chemicals in their clothes or bedclothes, set off by contact with candles or smoking materials? Reply #38. Mar 19 17, 8:30 AM |
daver852
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Spontaneous human combustion is a fairly well-documented phenomenon, but the so-called "scientific" explanations that have been put forward to explain it are simply ridiculous. Most are versions of the "wick effect," whereby melting fat serves as fuel, causing the body to burn like a candle. This explanation fails to explain how extremely the extremely high temperatures needed to reduce bone to ash are produced, or why the area surrounding the body is almost never affected. Reply #39. Mar 19 17, 10:37 AM |
| brm50diboll
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I would not attempt to propose a mechanism for this phenomenon, but I do agree with daver's criticism. Furthermore, adipose tissue is not entirely lipid. It is vascular (contains blood vessels) and therefore there is a significant water content, so it would not burn even as well as paraffin, and paraffin does not burn hot enough to turn bone to ash, as daver mentioned. Reply #40. Mar 19 17, 1:18 PM |
526 replies. On page 2 of 27 pages. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
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