Molecules Definition and 543 Threads

Hello, why much substances have one atom when aren't gas and 2 same atom united when are gas (for example N and N2, O and O2) ? Thanks!

What is the momentum of an oxygen molecule traveling at this speed? the speed was 484 m/s the molar mass of oxygen is M=.032 kg/mole Na= 6.022 x10^23 I do p=mv v=484 m=M/Na The answer should be 2.57x10^-13 but i keep getting 2.57 x10^-23

How can the bond angle in a molecules are measured ? The methods used to measure the angles and length b/w bonds.

Homework Statement Many diatomic (two-atom) molecules are bound together by covalent bonds that are much stronger than the van der Waals interaction. Experiment shows that for many such molecules, the interaction can be described by a force of the form F_{r} = A[ e^{- 2b( r - R_0 )} - e^{ -...

Hey all ! I've got a few questions regarding the Hartree Fock method which I'm not so sure about... Will HF result in a good estimate of the interaction energy between two Methane molecules ? and what about the structure and symmetry of Methane molecule ? (I know that as far as structure is...

Hi! I'm wondering what the effects of a variable mass of elementary particles on the rotational and vibrational energy-transitions would be like? Would they increase, decrease or stay the same? Thank you for your help! Regards

Just curious what the best way to pull off an image from Molden is? To me it seems that Print Screen is a bit of a silly way to do it; any suggestions?

the buckyball has between 20-60 atoms. This is a fairly large size. even if we "bounce" a photon or two off it, the molecule should not be effected. Thus can we use some method to find out which slit the molecule went through, without disturbing the interference pattern? or is it that, even...

have fullerene molecules (buckyball) been (quantum) entangled yet?

I just finished up my first class of chemistry, and have a question on something that I just can't figure out. The delta H of formation for diatomic molecules is 0. I just don't understand why this is. If there is a reaction, and O2 is one of the products, why is there no heat released when...

Could someone please explain the general idea of the Hartree Fock method to optimize the geometry (and energy) of a molecule. I understand that in the atomic case, one uses atomic orbitals and optimizes these, but in a molecule (especially polyatomic, say water or benzene) I am a bit confused...

So, I was brushing my teeth and started thinking about pi and how it is irrational. One thing led to another and I remembered Atom, by Asimov (which I haven't yet finished). Now, assuming pi is irrational, if we have a wheel with a radius of 1/2 (units don't really matter), and unroll it so that...

Homework Statement Why is <vx> = 0 this is a gas molecule Homework Equations The Attempt at a Solution I don't understand how the velocity could ever be zero?

hi, i need to explain how molecules of ethene combine together to form a poly(ethene) molecule? would it be because the double bond is broken and 2 bonds them placed on the outside of the Carbons (C)? if this is not correct could someone please let me know where I am going wrong! thanks!

Hi there, Ok from my lectures: Temperature is due to the Kinetic energy of molecules. Kinetic energy can be due to vibrational, rotational, translational and/or electronic motion. Now when you move an object from one place to another, aren't the molecules undergoing a nett translation...

Hi there! I'm studying that if r is the quantum number associated with the total angular momentum of a diatomic homonuclear molecule, then only odd or even values are allowed for r. Now, the selection rules for r requires a change of one unity, but if my molecule has only odd values for r...

Homework Statement What percentage of molecules in water at 300K will have a speed greater than 1 km/s (evaluate numerically)? Homework Equations The Attempt at a Solution Based on what we did in class, I take it I'm supposed to integrate the distribution from 1000 to infinity...

i was discussing with ma friend about the possibilities of inducing more vibration to the molecules in a solid matter... but we could not find a process to do that even though its not practical wanted to know some thing that is theoretical... hope some one is going to give new ideas..

Homework Statement In this problem, the surface tension S represents the work done to the water when increasing the water's surface area. The vaporization temperature Qvap represents the energy needed per volume unit to vaporize water at 100 degrees Celsius. We imagine that water molecules...

account for the fact that air molecules have a smaller mass? I have down in my notes something about if a larger particle was used then the average impulses would tend to 0, could someone please explain this? thanks a lot !

Homework Statement The molecular bond between the carbon and oxygen atoms in the diatomic carbon monoxide molecule can be treated as a spring with elastic constant k. The carbon atom has a mass of 12 amu and the oxygen atom has a mass of 16 amu, and the average separation of the two nuclei...

If buckyballs display uncertainty in the double slit experiment, shouldn't iodine gas molecules as well? An I2 molecule is certainly less massive than a buckyball. Yet why can we see I2 gas as a purple haze? I can see it, almost in the same way I can see my pencil, which has a very small...

1. Estimate the number of oxygen molecules in LTD under normal pressure and temperature. 2. I'm guessing you use PV=nRT to get the number of moles of gas in the room and work out the % of oxygen in the air, but I got a number which to me looks too small. 3. Volume of LTD is approx...

Homework Statement A 4.0 m^3 container of oxygen gas has a gauge pressure of 8x10^5 Pa at 25 degrees c. a) how many moles of oxy are present in the containe?r ANS: 1292 moles b)how many oxy molecules are present? ANS: 7.78E26 oxy (yes, i have the answers but i don't know how to get to them...

Unstable molecules - is the instability "relative" to environment? There are many highly unstable chemical configurations. Most chemicals, after all, would prefer to move from high-energy states to low-energy states. This is usually possible due to the presence of a reaction pathway that makes...

Homework Statement At a height of 300km above the Earth's surface, an astronaut finds that the atmospheric pressure is about 10-8 mmHg and the temperature 500 K. How many molecules are there per milliliter at this altitude? Homework Equations The Attempt at a Solution I first...

Say I have a molecule with two metal centers and some bridging ligands binding the two metal centers, how do I know whether the molecule is ferromagnetic or antiferromagnetic (or neither)? What exactly dictate whether this molecule would be ferromagnetic or antiferromagnetic?

Homework Statement Hullo I'm working through a textbook, and I've come across this expression which I don't follow at all.. the section is headed 'Velocity distribution of moledcules in a gas'. I follow it up until this integral, but I've not got a clue how they do it. I've had a couple...

Why does heat cause certain things to break into their basic elements?

Why do some atoms bind with other atoms of their own elements, such as O2 and N2, and why do others not? What property of these atoms enable them to do this?

This might be a stupid question, but it has me kind of confused. In diffusion, molecules will flow from high concentration to low concentration, and the explanation typically given is that in the laws of thermodynamics there is a net increase in entropy over time. But I am trying to think of...

This question has been bugging me for a while, I thought that it was due to the atoms electrons moving faster, making the atom basically also move around more.

Water molecules are polarized, so why don't the molecules in a glass of water simply line up with opposite + and - ends and come to a halt?

How do you figure out what the shape of molecules are. For example, Water. 1 part oxygen and 2 parts hydrogen with 104.45 degrees between the two hydrogen. That's what I want to figure out. I imagine it has something to do with the electrostatic force.

how can i know what the names of the molecules in this list:C3H8. SO3, F2, KBr (the numbers need to be little) thanks.

How do you determine the shape of molecules. water, as an example, the 2 hydrogen atoms are at a 104.45 Degree angle from each other. But how is that calculated? I'm assuming it has something to do with the ratios of the electrostatic forces between the 2 hydrogen and the oxygen.

Uranium nitride rips the hydrogen atoms off a carbon atom -- but unfortunately, the UN is destroyed in the process. http://news.discovery.com/tech/uranium-nuclear-power.html I don't why is considered new, since UN has been around for more than 25 years. It was considered for compact...

Homework Statement When forming a micelle, molecules such as fatty acids, detergents and lysophospholids form micelles on the basis that the cross sectional area of the head group (I'm guessing the polar part that interacts with water) must be greater than the acyl side chain...but what...

Homework Statement Calculate the mean spacing between hemoglobin molecules inside a red blood cell? Homework Equations Diameter of red blood cell = 5 microns 3*10^8 hemoglobin molecules in each red blood cell Volume of hemoglobin molecule = 8.71*10^-26 m The Attempt at a Solution...

Homework Statement For a biology lab dealing with chemistry, we are supposed to make models (ball and stick) of molecules, and then we need to write the structural and molecular formulas. The models should represent single or double bonds based on the molecular composition. The problem is...

Hello all, I understand that an increase in pressure yeilds an increase in temperature (in gases). However, I was wondering if extreme pressures can raise the temperature of organic molecules (such as the tissues in a human body) to melting point. Thanks!

So I'm trying to teach myself MO Theory and Spectroscopy. I was just wondering why symmetry was so important in understanding these and what characters are used to do. I know this is a broad question, but I've been reading a lot (Cotton, etc..) so I know they have to do with integrals and...

Homework Statement Estimate the average spacing between molecules of 1 mol of an ideal gas at a pressure of 1atm and a temperature of 300K. Homework Equations PV=nRT The Attempt at a Solution I was able to calculate the volume occupied by the gas (0.0246m^3). Using the ideal...

I wonder what is the technique that measure ionization potential for molecular systems experimentally ?

In the explicitly-unsolvable Hamiltonian for a chemical system, approximations are made to solve the energy of the system. In particular we see CNDO (ZDO), INDO and MNDO theories. CNDO - complete neglect of differential overlap; two-center electron integrals are zero. INDO - intermediate...

Hi All, What are the average distance of a ion and a water molecule when it is hydrated. 1/ for sodium? 2/ potassium? Thanks.

My lecturer writes the following in his lecture notes: “Van der Waal’s : Fluctuating dipole of molecules induces dipoles in molecules or other- wise neutral atoms (eg noble gases)” Does a fluctuating dipole refer to a dipole that is changing its orientation in space? How causes a dipole...

How to count molecules and determine density, partial pressure and total pressure? Homework Statement Consider three identical boxes each containing a different mixture of O2 and N2. In box #1 are 3 molecules of O2 and 7 molecules of N2. In box #2 are 1 molecule of O2 and 2 molecules of...

Homework Statement The speed of a group of molecules are 2, 3 , ... 11 km/sec. find the average speed of the group and also find the R.M>S speed of the group ? Homework Equations The Attempt at a Solution by summation of all 2+3+4+... 11 / 11 . is it right ... and how i find RMS...

Hi all, As sound travels through air, does the air molecules travel with the same speed as well? In other words, if sound is traveling in air at 340m/s, does it also then mean that the mean speed of all the affected air molecules is 340m/s? I personally do not think so. I guess that...