Ion Definition and 406 Threads

An ion () is a particle, atom or molecule with a net electrical charge.
The charge of the electron is considered negative by convention. The negative charge of an ion is equal and opposite to charged proton(s) considered positive by convention. The net charge of an ion is non-zero due to its total number of electrons being unequal to its total number of protons.
A cation is a positively charged ion with fewer electrons than protons while an anion is negatively charged with more electrons than protons. Because of their opposite electric charges, cations and anions attract each other and readily form ionic compounds.
Ions consisting of only a single atom are termed atomic or monatomic ions, while two or more atoms form molecular ions or polyatomic ions. In the case of physical ionization in a fluid (gas or liquid), "ion pairs" are created by spontaneous molecule collisions, where each generated pair consists of a free electron and a positive ion. Ions are also created by chemical interactions, such as the dissolution of a salt in liquids, or by other means, such as passing a direct current through a conducting solution, dissolving an anode via ionization.

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  1. D

    How many potassium ions pass through if the ion channel opens for 1.0 {\rm ms}?

    Homework Statement The biochemistry that takes place inside cells depends on various elements, such as sodium, potassium, and calcium, that are dissolved in water as ions. These ions enter cells through narrow pores in the cell membrane known as ion channels. Each ion channel, which is formed...
  2. T

    Penning ion source operating principle

    I'm sending this message to anyone who has knowledge about neutron generator. is there anyone who knows how does penning ion source works. I mean how could ions exit the holes but electrons can't exit. I didn't find any explanation about it on the web
  3. N

    Damaging lithium ion batteries

    So I have learned that all batteries have an internal resistance which will limit the current that it can output, so that you can't discharge a huge battery in a split second because of that internal resistance. But what I am wondering is, at what point is it dangerous to draw too much current...
  4. C

    Ion Thrusters - How much do they cost?

    Ion Thrusters which are used for space vessels, such as sending sattelites into space, how much do they cost?
  5. sweet springs

    Ion acccount in neuron after firing

    Hi. I am learning how neuron transmit current. I am wondering after firing sodium ions are rich and potassium ions are poor in neuron cell. How ion concentrations come back to the original states before firing? Thanks for your help in advance.
  6. X

    What Is the Concentration of SO4²⁻ When Al³⁺ Is 0.28M?

    Homework Statement The concentration of Al3+ ion in aqueous solution of Al2(SO4)3 is 0.28M, Then the concentration of SO42- ion in this solution will be? Homework Equations Al2(SO4)3 → 2Al3+ + 3SO42- The Attempt at a Solution What should i compare to start of with?
  7. X

    Chemistry How many moles of valence electrons are in 1 mole of nitride ions?

    Homework Statement The number of moles of valence electrons in 1 mole nitride ions are? Homework Equations Nitride ion- N3- The Attempt at a Solution The number of electrons are 8. Therefore number of moles should also be 8?
  8. E

    Positive Ion passing through a Magnetic Field

    1.Homework Statement BACKGROUND: A positive helium ion He+ (mass 6.7 x 10-27 kg, charge 2e) is released from rest from the surface of a +1000 V electrode, as shown in the diagram below. It crosses (in vacuum) the gap between the electrodes, passes through a small hole in a 0 V electrode...
  9. M

    Where can I find an Ion counter?

    I am trying to locate an ion counter/meter so I can run some tests on ionic air filtering units and get a sense of the ionic charge coming out. I am not directly affiliated with a university or scientific organization, but want to do this to satisfy curiosity and think the outcome would be very...
  10. B

    Nuclear Engineers Working in Plasma or Ion Propulsion

    Hello. I am wondering what the job field is like for nuclear engineers that aspire to work in plasma research and implementation or things like ion propulsion, etc. I do not want to work in a plant. Thank you.
  11. A

    Acceleration with Fe2+ ion and Fe3+ ion help

    Acceleration with Fe2+ ion and Fe3+ ion help! A sample of two different iron ions, Fe^2+ and Fe^3+, are accelerated by the same potential and sent through the uniform magnetic field of a mass spectrometer. a)Which ions moves faster after being accelerated. Justify with relevant equations...
  12. B

    Why Does the Common Ion Effect Increase Ksp for AgCl in the Presence of Cl-?

    I'm working Ksp problems comparing pure water solutions w/ those with an ion already present in solution. Example: AgCl and NaCl both in solution. The pure water Ksp for AgCl is given as 1.77x10^-10. The question is what the Ksp would be with .01M of Cl- already present. After working the...
  13. B

    Negative Ion Emission: Heat, Piezoelectric Effect & Object Differences

    Will more negative ions emit from an object (like a "negative ion generator") due to heat or piezoelectric effect or will they emit any way? Also, do certain objects give off more negative ions than others?
  14. P

    With what speed does the ion enter the magnetic field in a mass spectrometer?

    Homework Statement A mass spectrometer has a potential difference of 120 V applied to its accelerator plates. It is accelerating a positively charged ion that has a mass of 2.32 x 10^-26 kg. the ion then is directed into a uniform magnetic field of 0.17 T. The magnetic field is perpendicular...
  15. P

    A 1 Gev/nucleon ion beam strikes typical matter

    A 1 Gev/nucleon ion beam strikes typical matter ... In this thread: https://www.physicsforums.com/showthread.php?t=622502 the key to figuring out what will happen would seem well modeled by any study or analysis of a 1 Gev/nucleon ion beam striking matter (e.g. a baseball). The density...
  16. C

    Question Related to Solubility and Common Ion Effect

    So the question asks - What is molar solubility of AgCl in 0.1M HCl? Ksp = [Ag+][Cl-] ----> Ksp = 1.8x10-10 After setting up the problem we get... Ksp = (x)(0.1 + x) 1.8x10-10 = (x)(0.1) 1.8x10-9 = (x) So the resulting answer is a Molar Solubility of 1.8x10-9, which to me is less...
  17. AakashPandita

    When water can form an H30+ ion why can't it form an H4O2+ ion?

    Is it that protons tend to join other H2O molecules rather than forming H402+?
  18. T

    How many years until Ion Plasma thrusters are used on space ships?

    Thanks, just curious ever since I watched Prometheus.
  19. F

    Why does chlorate seem to break the pattern of polyatomic ions?

    Hi, I was reviewing the polyatomic ions, and on the third row of the periodic table they seemed to follow a pattern going from left to right on the periodic table. For example: Silicate = SiO44-; phosphate = PO43-; sulfate = SO42- For row 3 on the periodic table, it looks like each...
  20. 1

    Ion electron balancing problem

    Homework Statement The problem is given like this "A student unsuccessfully tried to balance the following equation: Cr2O72-+Fe3++H+→Cr 3+ +Fe 2+ + H2O Homework Equations The Attempt at a Solution First tried to find the oxidation no. -8...
  21. J

    Calculating the n=1 Energy Level of B4+ Ion

    What is the energy of the n = 1 energy level in the B4+ hydrogen-like ion? I need it to 4 significant figures... I know the equation is En=Z squared X -13.60 /n squared... however I can't work out the answer to four significant figs
  22. N

    In heavy ion therapy ,how do you determined the exact location of the tumor?

    In heavy ion therapy ,how do you determined the exact location of the tumor? 1.How position of any object can be determined by a nuclear detector. 2.Instrumentation involved in a heavy ion accelerator for cancer therapy.
  23. marcus

    Role of triatomic H ion (H3+) in early star formation

    H3+ The original mothercloud was mostly H2 and He. It didn't have molecular species containing C, N, and O that are good at radiating away heat they pick up by jostling each other when the cloud contracts. So it was hard for the early clouds to contract by their own gravity, because they...
  24. R

    Calculating pH from deltaG° and Ion Concentrations

    I've been working on this one for a few days, and I just can't seem to get the right answer. Consider the reaction I2(s) --> I- (aq) + IO3- (aq) Balanced= 3I2 + 6OH- --> 5I- + IO3- + 3H2O deltaG°= -153.8 kJ/mol The question: What pH is required for the reaction to be at equilibrium...
  25. C

    Atomic/Ionic Radii: Helium vs. Lithium+ (ion)

    I'm teaching periodic trends in a Gen. Chem. course, and it's commonly mentioned that the radius of an Li+ ion (90 pm) is smaller than that of the neutral Li atom (~160 pm), with the dominant reason being that the valence 2s1 electron was removed. The same trend shows up for the other alkali...
  26. T

    Charge density calculations of resonance hybrids of arenium ion

    In the diagram attached, the 3 resonance structures of arenium ion bonded to H electrophile are shown.I labelled the carbon atoms in one of the structures for convenience. From the diagram, the A and B carbons, and D and E carbons, have a double bond between them for two of the resonance...
  27. N

    Why is O=N-O-O- not a valid predicted structure for the nitrate ion?

    Hello! I was drawing the lewis structure for NO3- and was wondering why O=N-O-O- isn't a 'valid' predicted structure (Double-bonded O to nitrogen, a single-bonded oxygen to nitrogen, a lone pair on nitrogen, and a single-bonded oxygen to oxygen with a negative charge on the terminal oxygen...
  28. B

    If something becomes an ion, is its zeff changed?

    If some atom loses or gains an electron, is its effective nuclear charge changed? I would think that it would change, considering that having lost an electron the shielding effect weakens, making the zeff larger, but people are saying there is no effect? Is there some explanation? THanks! BiP
  29. O

    Can an Air Ion Tester Measure Positive Ions?

    http://www.ebay.com.hk/itm/370583387771?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649 I have tested it using a 1.3v battery, Once I have switch "ON" this tester, Let the positive end of battery touch on the square metal of the front panel and let the rear square metal of this tester...
  30. R

    Chemical and electrical gradient for ion X+

    Please check my answers. I tend to over-think and get simple questions wrong. A hypothetical cell membrane is positively charged on the intracellular side and negatively charged on the extracellular side. In this cell, the concentration of ion X+ in the intracellular space is high and in the...
  31. Biosyn

    Medical Ion Proton 1: A Chemical Engineer's Dream

    What do you guys think of the Ion Proton 1 developed by a chemical engineer named Jonathan Rothberg? It can supposedly sequence most of a human genome for around $1000 compared to the past where had it costed millions. I don't recall quite clearly, but I think researchers at IBM are...
  32. A

    Estimating Ion Pairs Produced by 5MeV alpha in UF6

    Hello, I'm attempting to work out the number of ion pairs produced by a 5MeV alpha particle in UF6 (in each of the solid, liquid, and gas states). Using the technique from my old radiation physics book (Turner 3rd ed) I should simply apply the Bethe formula -\frac{dE}{dx}=\frac{4\pi...
  33. 1

    MATLAB [MatLab] Edit Delete Help with ion beam with many charge states

    I'm simulating an ion beam with different charge states passing through two pinholes. I'm using random angles, from an external function, to evaluate the velocity components along the axes and solving the differential equation: O=[0 0 0]'; f = @(t,ys) [ys(4:6); O]...
  34. B

    Ion naming confusion with the bi prefix

    Ion naming confusion with the "bi" prefix I am little confused on when you use the "bi" prefix to denote the existence of a proton in front of an oxyanion. For example, I know that [HCO_{3}]^{-} is called bicarbonate as well as hydrogen carbonate. A problem arises when I try to define...
  35. B

    Ionic or covalent in tetrahydroxoaluminate ion?

    Consider the metal-ligand complex of the tetrahydroxoaluminate ion. [Al(OH)_{4}]^- In this ion, the aluminium is bonded with four hydroxides where each hydroxide is a ligand. My question: Is the aluminium-hydroxide bond ionic or covalent? I can think of the ionic one working in...
  36. 1

    Ion beam with different charge state of the same element

    I'm writing a script to simulate the transport of ion beam in a Thomson Spectrometer. My concern is that the program doesn't allow the passage of higher charge states through out the pinholes that I use to collimate the beam. I mean if I want to simulate a 3 charge states beam of C ions I will...
  37. C

    Do Dissolved Bases Form Ion Pairs in Water?

    I was told that when a base is dissolved in water, the ions form ion pairs so it is difficult to separate them completely; is this true? And if so, why wouldn't this apply to acids?
  38. C

    Half reaction/ ion electron method

    I have recently learned how to balance chemical equations using the ion electron method. However, I have some doubts.. Suppose the reaction takes place in an acidic medium; now how can we say that we are allowed to add an H+ or H2O molecule? I mean, where will these elements come from when...
  39. Z

    Increase Ion Wind: Is It Possible?

    Hello all, i doubt this but is there anyway now or in the future to increase ion wind to where it acts like and has the same strength as regular wind?
  40. A

    Is the fragmentation of Carbon ions mainly composed of alpha particles?

    I'm analyzing data taken from 500 MeV/nucleon Iron beam and 290 MeV/nucleon Carbon beam. When looking at the fragmentation that has occured, the fragmentation for the Carbon beam seems almost always be alpha particles (I though I would see some Beryllium as well). Does this mean that the Carbon...
  41. F

    Electrostatic charge between a na+ ion and a cl- ion

    I have the relevant equation, I just need to know the charges (in coloumbs) of the two ions so I can plug them into it. I thought that it would just be the equivalent charge of the one spare proton/electron, but that did not work so I guess it was a faulty assumption. I have not been able to...
  42. C

    Ion Pair Reagents: Partitioning into Non-Polar Phases

    I'm reading about ion chromatography at the moment and read that one method is to use an ion-pair reagent which pairs with the ionic analyte, forming a neutral compound which can then partition into the non polar stationary phase. If an anionic analyte pairs with a cationic ion-pair reagent to...
  43. R

    Specific heat of a heavy ion plasma

    I am surprised by the result when I estimate the specific heat of the plasma produced by heavy ion collisions in the LHC: C(plasma) ~= 2e5 J/(g-K) (Details below.) This is ~1e6 times greater than C(lead)=0.13 J/(g-K) (1). Did I make a mistake? If not, can the physics experts who read this...
  44. S

    Build an Ion Thruster: Research & Tools

    Hi my friends I wanted to build a ion thruster for some research projects. I searched in net and find out that there are a lot of papers relating to design and increasing performance of ion thrusters, but i couldn't find a build paper or site! Please if any of you knew about build requirement...
  45. A

    Calculation of ion flux across potential barrier

    Hello! As far as I know, the Eyring equation is used to calculate the speed of a reaction: k=\frac{{k}_{b}}{h} {e}^{\frac{-\Delta G}{RT}} In my course the teacher used this formula to calculate the flux of a species of ions across a barrier of potential, but I didn't understand very...
  46. Z

    Ion Pressure Theory: Can Negative Ions Lift a Metal Ball?

    Ok well hello there everyone yes, i am still a novice at this but i was wondering this would it be possible. If i had a metal ball and i charged the center of it positively and then have an external electrode on the bottom charged negatively creating negative ions that cover the bottom half of...
  47. Z

    Ion Density Theory: Can It Create Lift?

    Umm hello there I'm still a novice at this whole thing but i was wondering, would it be possible to have an area of air with a a small ball object within the center of that area and in this area an electrical charge is presented to create both positive and negative ions in it so that they will...
  48. P

    Using Anion Resins to Separate Cations: Exploring Ion Exchange Resins

    Homework Statement I am doing a lab called "Complexometric Determination of Cobalt" and am asked "Explain why an anion resin can be used to separate a mixture of cations such as Co(II) and Ni(II)" I have no idea. My textbook says that cation exchange resins are used to separate...
  49. J

    Coulomb Integral for Diatomic Hydrogen Ion

    Homework Statement What does the non-negativity of the Coulomb Integral for H2+ suggest about the relative strengths of the attractive electron-proton force and the repulsive proton-proton forces? Homework Equations N/A The Attempt at a Solution I want to say that it means the...
  50. T

    Need help using Ion Electron Method in acidic conditions.

    Using the Ion Electron Method (acidic conditions) I need to solve: MnO4- + C2O42- -> Mn2+ + CO2 So I tried doing: MnO4- -> Mn2+ And: C2O42- -> CO2 + 2H2O Then I balanced the oxygen atoms with H2O MnO4- -> Mn2+ + 4H2O And: C2O42- -> CO2 + 2H2O Then I added the...
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