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A nucleus has the following roles in an atom. It contains almost all the mass of the atom It is positively charged and hence keep the electrons in orbit via electromagnetic force (attractive) A nucleus contains protons which determine which element the atom is of That's all. And, no, it is safe to assume that nuclei don't move within the atom, they are ...


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Many things are aging even if not used, like lithium ion power cells. There is filter aging independent of the passed water volume. There is eventual growth of chemical and microbial stuff. E.g. chemical sediments on the active surface of antimicrobial silver causes deterioration of antimicrobial effect. Active carbon for organic traces and ionex resin of ...


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The membrane has plenty of holes that are a little bit bigger than small molecules like water. Bigger molecules or bigger ions like usual solutes cannot go through these holes. So water has the tendency to cross the membrane both ways. When a water molecule hits a hole in the membrane from the pure water side, it can cross it. Nothing prevents it. When a ...


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Esterification $\ce{R_1-COOH + HO-R_2 <=> R1-COO-R2 + H2O}$ has the equilibrium constant, expressed in compound activities: $$K = \frac{a_\mathrm{ester} \cdot a_\mathrm{\ce{H2O}} }{ a_\mathrm{acid} \cdot a_\mathrm{alkohol}}$$ The water activity is decreased by dissolved salts by 2 ways: decreasing the molar fraction of water by dissolved salt ...


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Gardeners often use a tennis ball for this purpose - it preserves a gap in the ice.


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Maybe a numerical example will help you. Let's start from pure water, with the following concentrations :$\ce{[H+] = [OH-] = 10^{-7} M}$. Now we will suppose you add $\ce{10^{-7}} mol$ $\ce{HCl}$ in one liter of this water. Suddenly, the concentration of $\ce{H+}$ should double. This is not possible in the long run. A part $a$ of these supplementary $\ce{H+}$...


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There are oils sold for swimming pools to slow or stop evaporative cooling . That would be a problem for air breathers like mosquito larva. I don't know anything about it because I went with 1" thick Styrofoam panels. That is what I currently have on my pond ( 10' X 5 '), works very well .I cheat a little and have 150 watt aquarium heater in the 700 ...


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A possible more natural solution allowing continuing oxygen exposure, use a layer of leaves resting on a frame (say wood branches). Supporting related comments can be found here, to quote: Leaves can be used to insulate plants from cold weather. To provide protection for plants, including container plantings, circle a plant with wire fencing. Then, stuff ...


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Why does each atom wait to turn into gas until they reach a particular electrode? There are no oxygen atoms or hydrogen atoms formed in the solution. There is also no "electricity" going through the solution. The processes happen at the electrodes because the cathode is able to provide electrons (to reduce hydrogen ions to dihydrogen) and the ...


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In electrolysis, why does oxygen only appear on the anode? Easy way to remember this is that oxidation occurs at the anode (both start with vowels), and oxidation implies a loss of hydrogen. If we lose hydrogen from water, we are left with oxygen. If you wish to understand it crudely, the concept is that anode the surface in the solution where the electrons ...


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$\ce{H2O}$ is not simply split apart by electricity, as you say. No ! What happens on one electrode is not related to what happens to the second electrode. Let's start by discussing what is happening on the negative electrode, the cathode. The negative electrode behaves as if it contains plenty of electrons ready to react with anything able to do it. It ...


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Electron transfer between the 'species in the solution' and the 'electrode' take place at the surface of the electrode. So, considering water with some acid Oxidation at anode: $\ce{2 H2O(l) -> O2(g) + 4 H+(aq) + 4e−} \quad E^\circ = \pu{+1.23 V}$ (for the reduction half-equation) This oxidation (electron transfer from water to the electrode) occur at the ...


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