John Cuthber

Yes. Because dioxin, with a vapour pressure near 10-^-9 mmHg is practically involatile so it isn't a vapour hazard. Any dioxin "in the air" is almost certain to be stuck to dust. Any filter that strips the dust will also remove practically all the dioxins. Why bother with activated charcoal? Yes. In the case of ozone , it reacts to give carbon monoxide . Charcoal will remove the other compounds- until the filter is saturated. It is difficult to be sure if the filter is saturated. Some materials are more strongly retained than others and you can have a situation where one material displaces another.

I'm fairly sure that what you propose is a breach of the laws of thermodynamics.

Hot copper oxide is used in classical chemical analysis to convert organic compounds to carbon dioxide and water. What mixture of products you get will depend on temperature, contact time, proportions and other stuff. Passing methanol vapour over hot copper (metal- not oxide) will produce formaldehyde. The commercial synthesis uses silver, rather than copper.

Iron does not dissolve in mercury.

No. Six divided by four is 1.5 ! Moderator Note This was a reply to a spammer so may seem to lack context!

To a good approximation; nothing ever fails in straight compression. You may find this next equation helpful. The (average) force exerted by an object when it comes to a halt is equal to the (average) force used to accelerate it times the ratio of the distance it was accelerated to the distance over which it stops. So, if I drop a rock that weighs 1 newton off a table that's a metre high and it comes to a halt when it hits the carpet which is 1 cm thick, the average force on the floor is 100N. It's also important to recognise that the "strength" (however you measure it) of the object which strikes a target isn't as important as people think. You can cut steel with water if the water is moving fast enough.

Would you like to try that again, but with more rational explanation and less dross?

Well, that's a matter of theology. The fact that the acceleration due to gravity at the Earth's surface (9.80665 m/s/s) is near, but not exactly, 10 m/s/s is down to whoever designed the Earth.

Not strictly a liquid but you can pour it... metal shot would also act as screening. I can't think of a solution involving any liquid that doesn't include sealing the phone in a bag or something (unless you don't care about ruining it). If you are going to seal the phone in a bag anyway, you might as well wrap it in foil.

I suspect it is very toxic to mobile phones. Mercury vapour will damage aluminium and solder.

Well, it's 6 HCl + 2Al --> 3 H2 + " 2 AlCl3 But that's hardly important. Both metals (indeed most metals) react with dilute acid to give hydrogen gas. However, if you take the solution of metal chloride and add an excess of ammonia solution you get different results. With zinc you get a precipitate of Zn(OH)2 but that dissolves when you add more ammonia. With Al you get a white precipitate of Al(OH)3 which doesn't dissolve when you add more ammonia. It's worth doing the reactions on known materials first so you get the "feel" of it. Having said that, Aluminium is about a third of the density of zinc, and that's often a pretty good way to tell them apart. Also, it is very common to find alloys that are a mixture of aluminium and zinc.

And my garden bonfire- which didn't. The common factor is fire, not lead. Some lead will have been boiled off into the air. And, by now it will have been washed out by the rain into the rivers.

I think the traditional response is " No shit, Sherlock". Would you like to compile a list of dusty old churches where that was not the case?

So far, that's just about the only thing Enthalpy has said here with which I agree. There are two issues. Decades of traffic will have dumped "new" lead on it and there will have been modern repairs. But the original "old lead" is valuable as a low background screening material

It's fairly clear that we could rebuild NDdP from aluminium and titanium. The question is why would we want to? Shouldn't we restore it as well as we can, and build new buildings in a modern style?

Interestingly, Google can't find where you asked them.

And, obviously, no tourist would go to a building that was in poor repair https://en.wikipedia.org/wiki/Stonehenge (That's the UK's most visited tourist attraction) or to a cathedral that was undergoing building work. https://en.wikipedia.org/wiki/Sagrada_Família (That's Spain's 2nd most popular tourist attraction) Timber is a composite material. The last lot lasted 800 years. Glued timber is known to last a long time https://www.cmuse.org/the-oldest-surviving-violin-who-made-it/ https://museumcollections.rcm.ac.uk/rcm_collections/guitar-belchior-dias-lisbon-1581/ And, as you have pointed out, they only have to make do with glued timber for a few decades while the oaks grow.

Well, if you wait... https://en.wikipedia.org/wiki/Osteoporosis what are you hoping to achieve?

It's the same church.

There is no need for everything to be "modern".

The x ray is more likely to hit an air molecule than an oil drop. That will give rise to all sorts of bits and pieces. Which one sticks to a drop will define the eventual charge. You can, in fact, set up the experiment to look at drops with either charge. However, Millikan was looking at the charge on electrons. And it was not strictly safe for him to assume that the positively charged entities had the same charge as an electron. So he looked at drops with negative charges.

What use do you anticipate making of the height of the object?

Thanks for the picture of a cloud of smoke not affecting people because it is a hundred meters above them. At least my approach has some basis in science. Yours ... less so. There are people who model this sort of thing for a living. https://en.wikipedia.org/wiki/List_of_atmospheric_dispersion_models Why not ask them about it? Wrong. Others won't. There are already questions being raised about the (ver rich) church being subsidised to repair their building. That money could be used for things that matter- like people- rather than a old building. Do you think that what will be seen as "gold plating" it will help?

Tacitly. And you are, I think given more information than you need.

What pictures? Anyway, since you seem to have ignored it Google tells me that Paris is about 100 km ^2 That's about 100,000,000 m^2 And atmospheric pressure is about 100,000 N/m^2 So the weight of the atmosphere in Paris is something like 10000000000000 N A newton is roughly the weight of 0.1Kg so that's a trillion kg Roughly a billion tonnes. Into which we disperse a few tonnes of lead. Giving a mean concentration (pessimistically assuming it's all released so fast that none escapes by dispersion on the wind or whatever) of a few parts per billion by mass. That's not good but let's see how much difference it makes. What's the background? http://www.euro.who.int/__data/assets/pdf_file/0020/123077/AQG2ndEd_6_7Lead.pdf tells me "Spot measurements in five French and four United States cities in 1984–1985 reported air lead levels ranging from 0.005 µg/m3 to 0.44 µg/m3 , the highest value being from Paris" So Paris in the 80s had lead levels of 0.44 µg per m3 And a m3 of air has a mass of roughly 1kg So that's a level of about 0.44 parts per billion by mass. And the fire released a few ppb (m/m) So it's a roughly 10 fold increase. Until the wind blows or the rain falls. So, for a few days the average lead concentration in Paris went up about 10 fold. Not good news, but hardly worth making a fuss over. Obviously, you need to look at firefighters' exposure. Practically nil because they are not stupid and wore breathing apparatus.