Molecules Definition and 561 Threads

It can be shown that if a hamiltonian is invariant under space inversion and if an eigenstate is non-degenerate, then the state is either even or odd in each position coordinate. So if there is a perturbation given by a uniform electric field, which has: H_1 = - \vec E \cdot \left( \sum_i q_i...

hey guys, could you'll help me with the following problem... Inside the leaf of a plant, water vapour passes from the liquid phase to the vapour phase at the walls of the mesophyll cells, as shown in the figure. The water vapour then diffuses through the intercellular air spaces and...

does water molecules exist in KOH(aq)?

Take Nitric Oxide for example. When I've drawn out the Lewis structure, how do I know whether the unpaired electron belongs in the nitrogen or the oxygen? Are both variants of the NO Lewis structure acceptable? Furthermore, if both of these variants are accepted, is there a "resonance" of NO in...

Hi, you don't have to do this by yourself(if you do this, that would be really nice but we both would have to be online at the same time probably). But there is probably a link online which teaches how to draw molecules. Hint: the one where there are dashes signalling the bonds and atom's...

Hello In DNA, thymine and adenine molecules are attracted to each other. The solid lines show bonds between atoms in the same molecule and the dotted line shows bonds between atoms in different molecules. Atoms in the same molecule are separated by 1e-10 m. If the net charge on the H and N...

I mean, I know that they move faster the more energy there is, but why do they move at all in the first place? Would a single molecule move if gravity wasn't acting on it and it didn't touch anything else?

Hello :D How do chemists make molecules such as those in commercial products id est benzyl peroxide? -Thanks!

My text doesn't seem to talk about average separation of molecules, so I can only get so far with this problem. Help would be appreciated. The problem reads: From the average separation between air molecules at STP, and their mean speed, estimate how long it would take one molecule to move...

Hello, I was just taking a shower when this question came upon my mind, what would happen if all the electrons stopped their motion? And, I don't know, but when molecules are created, wouldn't it cut off a path of an electron from the side where atoms have been combined?

I have a few questions about polarity of molecules, first off i know that soaps/detergents have both a hydrophobic and a hydrophilic end which are essential to is operations but is there anything else about its shape or electronegativity that I am missing, like is it polar/non-poalr cause i...

I am a little confused. I was talking to my teacher a couple days ago, and he asked me to put the following three into order of velocity (greatest first): 1. Average velocity of the molecules in a gas (AV) 2. Most probable velocity of the molecules in a gas (MPV) 3. RMS (root mean square)...

First of all, sorry if I put this in the wrong board. Now, I have to do as much expreriments (for a school project) that would help to prove any information about molecules, that is very important to me, so if you know any experiments that would fit, then could you please write in here, or...

say for example, a question states that you have 18 g of H20 which is obviously one mole. now if they asked how many molecules of water you had, you would just multiply the one mole by avagadros number (6.022 * 10^23) to get that answer. if they asked how many atoms of water, would it be...

How we can face the speed of the molecules on the gas kinetics theory and the speed barrier of light ? because v=sqrt(3kT/m) were k is boltzman T = kelvin and m = mass of the element remember the huge T of the big bang

How is it that researchers are able to synthesize any complex molocuel, and know what it does? I mean is it just through random discoveries that biology is advancing or is there some other way? It is just the complexity of polymers is so great especially in cells. Even for relatively simple...

i know that the molecules in the "freedom" form that have charges equal 0. but i wonder why the molecules still moving to create the diffusion and the effusion? some one please explain to me. thanks:!)

:confused: What do you call a large organic molecule made up of repeating subunits? I would greatly appreciate it if someone could answer this for me. I am so confused. Please help. Thanks!

I have been having difficulties with this problem and I was wondering if I could get some help with it. Q. What is the rms speed of nitrogen molecules contained in a 7.0 m3 volume at 4.20 atm if the total amount of nitrogen is 1600 mol? I figured I would have to use this equation to solve...

Hi, I'm not quite sure about this question: 'How many Ways can 6 distinguishable molecules be placed in 3 different energy levels with 3 molecules in the 1st level, 2 in the 2nd level and 1 in the 3rd level, ignoring energy required?' If it was just how many ways to place them in 3...

The question is the title.

anyone here have knowledge on computing Lennard-Jones potentials for molecules using periodic boundaries versus doing it on the 3D surface of a hypersphere?

A box is separated by a partition into two parts of equal volume. The left side of the box contains 500 molecules of nitrogen gas; the right side contains 100 molecules of oxygen gas. The two gases are at the same temperature. The partition is punctured, and equilibrium is eventually attained...

hi all if you have a cylinder with helium and argon in it, and the mixture is at equilibrium, with a temperature of 150 degrees celsius. what is the average kinetic energy of each gas molecule?, and what is the rms speed of each type of molecule? im aware of the theory behind this, but it...

Why do all the protein molecules in our bodies rotate polarized light in one direction only? If I injected proteins of the opposite polarization into my bloodstream would their be a strong immune reaction? Also,what would happen if one of the organs in my body - for example the liver - was...

I have absolutely no idea how to do this question. I've tried several different ways.. tried using the equation: P = (1/3)*(N/V)*2*((3/2)kT) Then using the idea that: P = F/A No luck. I think I'm doing things wrong. Does this have something to do with internal energy? (U = (3/2)nRT)

Roughly 20% of the molecules in the air are oxygen molecules. The oxygen molecules are needed for life processes in a person's body. What is the probability that in one breath, one might fill his lungs with a volume of air that has no oxygen in it? How does one go about doing this...

hello. i will be appearing for my a levs in a couple of months and this is a 'design experiment' question i need help with. i haven't ever designed an experiment and help will be appreciated. Question: 'Alpha particles from a particular radioactive source have a range of about 6 or 7 cm...

Yesterday in my chemistry class we were discussing right vs. left handed organic molecules and such and it got me wondering. First off, is there any way to make a right handed molecule left handed? Second, just how much would such a process cost? Thanks.

Hi, can anyone tell me how to estimate width of one stearic acid when it is in water. /\/\/\/\/\/\/\/\-COOH <- i want the width going up and down.

I was involved in a hot debate about burning-in of audio cables. It's a line that many cable manufacturers have used for years and years, and they basically tell unsatisfied customers "You have to use the cables for over 200 hours before they become accustomed to playing the sound"... Now, I...

When classifying as to whether an atom, molecule, element, or compoud, what would the following be? -H20 -H2 -C6H12O6 (glucose) -N2 I guess i am kind of confused as to the difference between molecules and compounds. I thought water was a molecule, but according to the definition of a...

Hi can someone explain to me why is N-Acetylpiperidine is a weaker base than 1-aza-2-2oxobicyclo[2.2.2]octane ? Is it something about the ability to protonate the molecules ? thank you

What about the molecules and bonds of transition metals make them (such as gold) such good conductors? I'm in AP chemistry, so we may have gone over it, but I don't know right now.

I have the following problem, which seems easy, I just cannot get my brain around it... Assume that 30.0 cm^3 of gasoline is atomized into N spherical droplets, each with a radius of 2.00\times 10^{-5} m. What is the total surface area of these N spherical droplets? How do I find the...

can you really have nothing, for example you have two balls one meter appart, you can say that there is nothing between them, however there are air molecules between them right, well couln't there be other smaller particles between the air molecules? and then smaller particles between those, in...

i have a multi-part question which is fine except for two areas. 1) how many oxygen molecules traveling at this speed (i already have the speed calculated) are necessary to produce an average pressure of 1.00 atm? 2) calculate the number of oxygen molecules that are actually contained in...

more covalent?? hi. i saw this problem while doing some chem revision. they wanted me to point out and explain which one of the two is "more covalent". these are my personal explanations.. but i am not sure if I am correct or am i using the right way to do it.. pls feel free to give me your...

Vsepr Theory Hey Guys! How are u guys doing today? I was wondering how do we know dat BeF2 is polar?..i drew it out by using the VSEPR theory..but what confuses me is dat BeF2 ionic..can we still use VSEPR theory to draw it out? Tanya Thank you in advance! :smile:

Experiments show that rubbing an acetate strip with cotton imparts a negative charge to the strip. what are some of the attraction of some of the liquid streams to the charged strip. (The liquids being: water, 2-propanol, acetone) other experiments shown that a positively charged strip...

Air at STP has pressure p = 1 atm = 1.013 ×105 Pa, and temperature T = 273 K. Use the ideal gas law to determine the number of molecules in a cubic meter of air. I have tried many different numbers and can't seem to get the correct answer. I guess I should use the formula PV = NkT so...

I was just wondering, what are the rods composed of that hold the molecules together in substances such as water? You have hydrogen and oxygen atoms, but I always see these life-size models of the molecules being held together with rods in between each atom - with no explanation of what they...

Hello, I am researching sound at Concordia University, Quebec. Recently, my mind was wondering and I thought about sound being produced by the air molecules bumping into each other. I began to wonder what else could do the same thing. Does light have contact with the air molecules in this...

Why is it that for the case of two polar molecules the dipole moment does not depend on the electric field from the dipoles?

I'm trying to do some thought experiments involving ionized gas. More specifically, I'm thinking about ionized air. For the sake of argument, let's just imagine that we're ionizing the air by sticking a pin out of a Van de Graaff generator that's positively charged. My main question is this...

This was a national science quiz question: What's the smallest amount of molecules for water to have the properties of a fluid. a)1 molecule b)2 molecules c)6 molecules What's the answer and why?

Hey I was just wondering if you know the height of the atmosphere, and the pressure that atmosphere creates on the Earth (1 atmosphere), then how would you approach calculating the number of molecules in the atmosphere? I was thinking of using the PV=NKT formula, where K is boltzmann's...

i have to type up some molecules, and i don't know how to make the numbers smaller. for some reason, i can't make the 2 in HgCl2 small. can anyone help me?

I've just recently read an article, about sugar molecules that form inside of cells, that was really shocking. Apparently, current research has discovered that some of these sugar molecules are many time more complex than DNA! What do you guys know about this? What is the purpose of these...

Hi Everyone i have been having problems with my school calendar lately, and had to change one course to a grade 12 chemistry, i just attended the class for the first time friday, and it has been 2 weeks since it started. My teacher is going all out with no mercy and giving me an assignment...