jdurg

Yeah, I did some further research and by polishing a cadmium rod I did no more harm to myself than if I had smoked a cigarette. And I quit smoking cigarettes a few weeks ago so I'm not concerned at all. Polishing/sanding cadmium isn't something that I'm going to do every day, but that one time of doing it is not going to suddenly make me drop dead. lol.

I wound up polishing the cadmium by first dipping it into an acidic cleaning solution which ate away a little bit and the surface and helped remove surface dirt. I then went and got some polishing compound which is a really thick, gunky stuff that does a good job on smoothing things out. With the thick past over the surface, I then went and used a metal sanding cloth and LIGHTLY polished the metal. It worked out great as the surfaces are a little rough still, but HIGHLY reflective. Also, the past helped keep all the sanded metal in the gunk. When I was done I just washed the cadmium first in some pure isopropanol, then in a ton of water to make sure all the compound was removed. I dried it off and placed it back in the container after throwing away my gloves and anything that touched the cadmium laced goop.

Ahhh. That's fine then. I can just do the 'sanding' and polishing either completely underwater, or using a very damp cloth while wearing gloves. To treat the wastewater solution, I could probably acidify it and then add sodium carbonate to it to ppt out an insoluble cadmium carbonate.

That's true. But since both the nickel and cadmium carbonates are insoluble, I don't see how the Cd could displace the Ni since the Cd would be 'trapped' into a ppt. Also, if you just add the Na2CO3 into the acidic solution, it will also neutralize the solution. I'm just trying to understand what it is that you want. Do you want the nickel salt, or the pure nickel metal?

Hey guys, YT's thread in regards to cadmium reminded me of something I wanted to ask. In my element collection, I have a bunch of cadmium rods. However, they are old rods and have a lot of oxidation on their surface, and some show a red color from when I chiseled them into smaller pieces on a brick. The ends of a few of the rods have maintained a beautiful shine to them, and I'd like to polish a few of the rods in there to bring out the beauty of the cadmium. Sadly, I'm not sure what the best way to do this would be. With the toxicity of cadmium, I am not going to bring my dremel to it in order to polish it. I was thinking about taking some water and making it very damp, and then putting a rubbing/polishing compound on the surface to remove the oxidation. If I'm wearing rubber gloves, I shouldn't have to worry about the toxicity, correct? If it's damp there will be no dust flung into the air. The dust factor is why the dremel is staying locked away.

I would think that you could dissolve the metal into an acidic solution, the neutralize the pH. If you slowly add sodium carbonate to the resulting solution, CdCO3 will ppt out first since its solubility is MUCH lower than NiCO3. (Ksp NiCO3 = 6.6x10^-9 while that of CdCO3 is 5.2x10^-12). So you should easily be able to slowly add the carbonate to a neutral solution and watch the cadmium ppt out, then when you add one more little crystal and nothing ppts out, the solution should then be full of the nickel ion. Would this be doable for you? Oops. I just now read that you don't want any suggestions. Sorry.

That is why it's so VERY important to specifically define every term you use. I know some people who will see a layer of ice on top of a lake and say that the lake is frozen. I only consider a mass of water frozen when it is solid 100% throughout. So to me, that lake isn't frozen. Only the layer of water on the top of it is.

Yeah, I wouldn't want to have a tankful of Nickel Carbonyl ANYWHERE near me.

Yup. Pretty much anything to the left, or beneath, the line is a metal, and anything to the right, or above, the line is a non-metal. Those elements which are right on the line are typically considered as 'semi-metallic' substances such as antimony, silicon, germanium, tellurium, etc.

Hence the use of vinegar. Heck, even baking soda would work. You just need something that will dissolve in water and form ions. Na2CO3 will readily dissolve in water and conduct a charge so the electrolysis will happen just fine.

You could probably use some vinegar if you want to do it cheaply.

Two words; Mercury Fulminate.

Yeah. I think the movement of air as you either bring the hammer back, or breathe while near the pile would make it go BOOM!

Yeah, but when the dolphin is moving in a wave pattern, is he without mass?

A-u! Get away from my gold! C-u later Copper! Don't forget to P-b 4 you go to lead! N-a way you look at it, Sodium is very reactive!

The wave particle nature was easy for me to get as well, it's just that it always seemed so contradictory to me that an electron is both a particle AND a wave at the same time.

I'll just give you some warning: The more in-detail you get with subatomic particles, the more it can get incredibly 'out there' and really mess with your mind. (That whole dual particle-wave thing still makes my brain go crazy. )

Well, you also have to remember that 'coldness' doesn't flow. Heat will flow from one object to another, but cold will not 'flow'. Things only feel cold because you sense the heat moving from your body into the thing at a lower temperature. Water also has a very high specific heat capacity. It takes a good amount of energy for one gram of water to change one degree Kelvin. For the cooling, the water has to give out about 4 kJ (I can't remember the right unit) of energy per gram of water in order to drop one degree Kelvin. It doesn't matter if the water's at 90 or 9 degrees Celcius. It still needs to 'give away' that energy to drop in temperature. So the amount of energy that cold water has to give up in order to freeze is a lot less than the amount of energy that hot water has to give up in order to freeze. The only way to speed up the freezing process is to put the water in direct contact with something that has a lower specific heat. This way it can transfer its energy much quicker. With the hotter water there is some convection going on as the water at the surface will cool and move down to the bottom of the container since colder water is denser than warm water. However, less noticeable convection is occuring with the colder water as well. With the boiling water, when you take it off of the heat source and put it into the cold, the boiling process will cease and you'll lose any added 'loss of volume' due to the boiling. Evaporation will also soon cease as the air will become saturated with water and you'll see it condensing out and forming a fog. This air which is initially warmed up will also be cooled down by the massive amount of cooler air surrounding it. Therefore, after the first few seconds of being out there, the advantage of the higher water vapor levels will soon break down. Scientifically speaking, if you have two containers of water that are exact in EVERY single manner except for the temperature of the water inside those containers, the hotter water CANNOT freeze any sooner than the cooler water. This is providing that you have the same container with the same insulation in the same environment with the same volume, etc. etc. As for why the boiling water thrown in the air seems to freeze, I think I have an idea on why that happens. When you throw water in the air, the surface area increases dramatically. With boiling water, it means that more hot water is exposed to cooler air. As a result, the temperature of the air surrounding the hot water will increase allowing more water vapor to exist. However, since there is so much more cold air out there, the air temperature will soon drop again causing all that water vapor to condense back into water and ice crystals. As a result, you'll see the ice crystals forming from the condensing water vapor. With cold water, it won't raise the temperature of the air appreciably so you won't get a sudden saturation of water vapor. No water vapor means no water to condense out which means no appearance of ice crystals. The ice has an easier time forming out of condensed water vapor because the mass of the water is less than it would be in the case of a puddle.

The amount of water that cold air can hold is VERY small, so evaporation will not play any significant role.

Really, ammonium triiodide isn't stable at all. If you look at all the Nitrogen trihalides, the stability depends on the strength of the N-Halogen bond. NF3 is VERY stable because the nitrogen-fluorine bond is pretty strong. The N-Cl bond is weaker, N-Br is even weaker, and N-I is incredibly weak. As a result, that 'weakness' results in instability. Ammonium/Nitrogen triiodide is able to remain stable when wet, however, because the ammonia atoms are able to solidify that N-I bond. I think they help relieve the stress on the bond which allows it to remain intact. It still decomposes, but not at a high rate of speed. When the compound dries, any stability is lost. The compound becomes 'metastable', I'd say, meaning that it won't suddenly decompose unless provoked. Any slight provocation will cause the bonds to break and the compound to explode. The reason for the explosion is because you have a solid reactant decomposing into multiple gaseous products and releasing a great deal of energy when doing so. (The products released are nitrogen gas, iodine gas, and some remnant ammonia gas as well). Any time you have more gas molecules forming than you have solid reactants decomposing, you have a great chance of an explosion. (Hence why TNT is a good explosive. The solid crystal decomposes into all gaseous products). Ammonium/Nitrogen Triiodide is classified as a High Explosive, I believe, due to the nature of its 'KABOOM'. It's just not used in the same manner as TNT, TNP, Nitroglycerin, etc. since there is really no way to transport the triiodide molecule intact, and generation on site takes way to long and is not 'cost effective'. The decomposition is caused when one of the Nitrogen-Iodine bonds are broken. It takes very little energy to break that bond, so any slight movement will cleave it. I'm not 100% sure on this, but I think that when the bond is cleaved it forms a 'free radical' Iodine atom to form which then goes and causes another bond to cleave. Kind of like a chain reaction in nuclear fission. Once one molecule decomposes, it causes other molecules to decompose and so on and so on.

I've noticed the same thing. About a year ago I began doing pushups/situps/pullups every night. I'd do about 25-50 of each in an effort to remove some fat and increase muscle mass. After about two months of this, I noticed nice definition and a definite increase in my muscle size. Sadly, I got lazy and quit doing all that working out. My muscles definitely regressed during that time, so upon quitting smoking two weeks ago I decided to start the pushups/situps/pullups again. After two nights of this work, my muscle size and definition was back to where it was before. It was amazing. I couldn't believe how quickly it all came back. I'm still incredibly sore and can't straighten out my arms without pain, but it's pretty remarkable. I also noticed that after doing a bunch of pushups, my hands wouldn't respond as quickly to nerve impulses. I had a bunch of shakes and couldn't grip anything tightly. I even had trouble carrying a glass of water. I thought that was odd, but I attributed that to muscle strain/tiredness and a major build-up of metabolism byproducts in the muscles.

Hi there. I've got a question about quitting smoking and the resulting withdrawal. I was a smoker for about 5 years at a rate of close to a pack a day. (Sometimes more, sometimes less). About two weeks ago I finally decided to quit smoking. It's not worth the money to continue to smoke, and frankly I just sick of being 'owned' by the cigarette. Since quitting, I've gone through the typical withdrawal symptoms. I'm cranky, I'm irritable, and I'm fighting off cravings left and right. Nicotine gum is helping, but it's not a cigarette. To help myself go through the withdrawal, whenever I want a cigarette I force myself to do 50 situps or 50 'half' push-ups. (Where its the knees on the ground and you're relaly only pushing up half your body). I figure this will be a good way to increase muscle mass, fight off the weight gain associated with quitting smoking, and the help reduce the cravings. (Since doing a bunch of situps/pushups really hurts after a while). Anyway, since I quit smoking two weeks ago, I've been having a LOT of trouble going to sleep. I just can't seem to fall asleep anymore. I get really tired and lay in bed, but it takes me a good three hours to finally fall asleep. I've tried everything; sleep aids, a shot of bourbon, music, you name it. Is this normal? Does mild insomnia generally occur when you quit smoking? Also, why is it happening and when should I expect it to go away? Thanks.