Saturday

September 20, 2014

September 20, 2014

Number of results: 29,995

**Chemistry**

Neutron diffraction is used in determining the structures of molecules. (a) Calculate the de Broglie wavelength of a neutron moving at 9.00% of the speed of light. __ m (b) Calculate the velocity of a neutron with a wavelength of 65 pm (1 pm = 10-12 m). __m/s
*October 21, 2008 by Rita*

**chemistry ap!!!**

Neutron diffraction is an important technique for determining the structures of molecules. Calculate the velocity of a neutron needed to achieve a wavelength of 0.989 Å. i used the equation and got 4.37, but its not right! pleas help someone
*October 19, 2011 by kela*

**chemistry**

assuming that a neutron star has the same density as a neutron, calculate the mass in kilograms of a small piece of a neutron star the size of a spherical pebble with a radius of 0.11mm
*May 4, 2012 by Karon*

**chemistry**

Assuming that a neutron star has the same density as a neutron, calculate the mass in kilograms of a small piece of a neutron star the size of a spherical pebble with a radius of 0.30mm .
*February 9, 2014 by Anonymous*

**Chemistry**

A beam of neutrons (mneutron = 1.6749 x 10^-24 g) has a velocity of 1.44 km/hour. What is the wavelength of the neutron wave? The answer is 993 nm. I tried to use 1/2mv^2=hc/lambda but I got 1483.5 m
*December 8, 2008 by Shaniquaa*

**chemistry**

if the radius of a neutron is 1.0 x 10 minus 13cm calculate the density of a neutron in g/cm 3
*May 4, 2012 by Karon*

**Physics**

The interatomic spacing in a crystal of table salt is 0.281 nm. This crystal is being studied in a neutron diffraction experiment, similar to the one that produced the photograph in the figure. How fast must a neutron (mass = 1.67 x 10^-27 kg) be moving to have a de Broglie ...
*April 22, 2012 by Matt*

**Physics**

"A wave travels from one medium to another, and the wavelength decreases. What happens to the velocity and the frequency?" I know that frequency will remain the same, because it is controlled only by the source. But does the velocity decrease? According to Snell's law, ...
*July 22, 2010 by Stuck*

**physics**

Calculate the frequency in hertz, wavelength in nm, and the velocity in m/s of light inside a material with a refractive index of 1.39. In vacuum, the light has a wavelength of 514.5nm
*April 5, 2011 by noel*

**physics**

5)a. Electrons accelerated by a potential difference of 12.23 V pass through a gas of hydrogen atoms at room temperature. Calculate the wavelength of light emitted with the longest possible wavelength. b. Calculate the wavelength of light emitted with the shortest possible ...
*April 13, 2008 by Sandhya*

**Physics (Simple Frequency Question) Reply SOON!**

I know that... wavelength = velocity * frequency frequency = velocity/wavelength If I have the voltage and the wavelength, does the voltage count as the velocity to find the frequency? If not, how do I find the frequency when I know the intensity, wavelength, and voltage? Thanks!
*May 8, 2009 by Judy*

**physics**

The volume of a neutron is about 10−45 cubic meters. Suppose you packed the number of neutrons you found for problem 4 into a cube so that the neutrons touched edge to edge. How big would the cube be? (Hint: Problem 4 states that a neutron star has a mass of 3.4×1030 kg ...
*November 27, 2011 by Anonymous*

**Chemistry**

At what speed must a neutron travel to have a wavelength of 9.2 pm?
*June 12, 2011 by Lance*

**physics **

what is the wavelength of neutron (m=1.67x10^-27kg) travelling at 3.0x10^4 m/s?
*June 16, 2013 by ceci*

**Physics**

A neutron collides elastically with a helium nucleus (at rest initially) whose mass is four times that of the neutron. The helium nucleus is observed to rebound at an angle θ'2 = 44° from the neutron's initial direction. The neutron's initial speed is 7.0 105 m/s. ...
*March 7, 2010 by Ben*

**Physics**

A neutron collides elastically with a helium nucleus (at rest initially) whose mass is four times that of the neutron. The helium nucleus is observed to rebound at an angle θ'2 = 44° from the neutron's initial direction. The neutron's initial speed is 7.0 105 m/s. ...
*March 7, 2010 by Ben*

**chemistry**

A particle wavelength (λp) of a proton is 10-12m. What is the velocity of this proton [m/s]? To achieved the velocity that you just computed, what must have been the potential difference (V) through which the proton was accelerated? An electron of wavelength 1.74*10-10m ...
*March 23, 2013 by schoolgirl*

**General Physics**

A neutron collides elastically with a helium nucleus (at rest initially) whose mass is four times that of the neutron. The helium nucleus is observed to rebound at an angle è'2 = 45° from the neutron's initial direction. The neutron's initial speed is 6.6x10^5 m/s. Determine ...
*October 30, 2008 by Scott*

**chemistry**

Atoms of ionized lithium gas (Li2+) are struck by neutrons moving at a velocity of 1.46e5 m/s. Calculate the shortest wavelength in the emission spectrum of Li2+ under these circumstances. You can assume that all electrons start in the ground state. Enter the wavelength in m:
*March 23, 2013 by schoolgirl*

**physics**

A neutron collides elastically with a helium nucleus (at rest initially) whose mass is four times that of the neutron. The helium nucleus is observed to move off at an angle =45. The neutron's initial speed is 3.8×105 .
*March 29, 2010 by Anonymous*

**PHYSICS**

A nuclear reactor contains nuclei that fission when bombarded by slow neutrons. The fission reaction produces fast neutrons which need to be moderated (i.e. slowed down) in collisions before they can cause further fissions. In this problem we consider a reactor which uses ...
*March 28, 2011 by Megan*

**CHEMISTRY**

What would be the uncertainty in velocity (miles/hr) of a neutron beam particle if the position can be measured within +/- 25 angstroms. The rest mass of a neutron = 1.67493 X 10^-27 kg or 1.008664904(14) amu. I know you have to use the heisenberg uncertainty principle: (...
*November 7, 2007 by Jacob*

**physics**

Assume that the mass of a neutron star is 1.5 times that of the Sun and the radius of the neutron star is 10 km. Ignore effects of Special Relativity. What is the approximate speed at which an object released from far away (at zero speed) reaches the surface of a neutron star...
*December 25, 2013 by Al*

**Physics**

I am having some trouble with some questions and need some help. A neutron with a mass of 1.68 x10(-27) exponent kg moves from a nuclear reactor with a velocity of 3.22 x10 (3) exponent m/s. What is the Broglie wavelength? Also, I need to write tge complete electron ...
*December 4, 2009 by Doly V*

**Physics**

A neutron collides elastically with a helium nucleus (at rest initially) whose mass is four times that of the neutron. The helium nucleus is observed to move off at an angle of 45 degrees. The neutron's initial speed is 5.9×105 m/s. Determine the speeds of the two particles ...
*October 8, 2010 by Bartholomew*

**college physics**

In a nuclear reactor, neutrons released by nuclear fission must be slowed down before they can trigger additional reactions in other nuclei. To see what sort of material is most effective in slowing (or moderating) a neutron, calculate the ratio of a neutron's final kinetic ...
*March 18, 2010 by Kyle*

**physics**

A tuning fork produces a wave at 280 Hz and with a wavelength of 1.5 m. Calculate its velocity.
*July 8, 2011 by wendell*

**science**

Calculate the de Broglie wavelength of a 0.44 kg ball moving with a constant velocity of 26 m/s (about 60 mi/h).
*April 2, 2013 by annie*

**Chemistry**

Calculate the de Broglie wavelength associated with a body of mass 1.5 kg moving with a velocity of 100m/s.
*October 21, 2012 by Sparkle*

**Physics**

This is a very confusing question and I have no idea how to tackle it. - In a nuclear reactor, neutrons released by nuclear fission must be slowed down before they can trigger additional reactions in other nuclei. To see what sort of material is most effective in slowing (or ...
*October 30, 2009 by Sal*

**physics**

A neutron in a reactor makes an elastic head-on collision with a nitrogen atom that is initially at rest. (The mass of the nitrogen nucleus is about 14 times that of the neutron.) (a) What fraction of the neutron's kinetic energy is transferred to the nitrogen nucleus? (b) If ...
*October 28, 2012 by heather*

**science**

Where does the neutron of heliam come from although hydrogen has no neutron?
*November 12, 2007 by Adina*

**physics**

A neutron, a proton, and an electron are initially at the same distance from a relatively large stationary nucleus moving at a constant velocity. Assume the masses of the proton and neutron are equal. 1. Which is the first particle to reach the nucleus? 2. Which particle ...
*March 23, 2008 by Karen*

**PHYSICS!!!**

A neutron, a proton, and an electron are initially at the same distance from a relatively large stationary nucleus moving at a constant velocity. Assume the masses of the proton and neutron are equal. 1. Which is the first particle to reach the nucleus? 2. Which particle ...
*March 23, 2008 by Karen*

**Chemistry**

What is the de Broglie wavelength of an oxygen molecule, O2 traveling at 521 m/s? Is the wavelength much smaller or much larger than the diameter of an atom. (on the order of 100 pm) De Broglie wavelength = h/mv h = Planck's constant in J*s. m is mass in kg. v is velocity in m...
*November 3, 2007 by Lauren*

**susane**

I have a question concerning waves. What effect does increasing the tension in a vibrating string have upon wavelength? I was thinking that as the weight increases more standing waves are created. As more standing waves are created, the wavelength decreases. I have one more ...
*February 3, 2007 by Physics*

**physic**

Neutron stars are extremely dense objects with a mass comparable to the mass of the sun but a radius of only several thousand meters. Consider a neutron star of mass M = 1.99e+030 kg and a radius of R = 10 km. g = 1.3279e12 m/s Assuming uniform density, how much would 1.1 ...
*May 23, 2007 by x*

**College Physics II**

1) An electron moving with a speed of 2.84E+6 m/s has the same momentum as a photon. Calculate the de Broglie wavelength of the electron. 2) Calculate the wavelength of the photon.
*November 25, 2010 by VJC*

**Chemistry**

A 0.22-caliber handgun fires a 27-{\rm g} bullet at a velocity of 765 {\rm m}/{\rm s}. Part A Calculate the de Broglie wavelength of the bullet.
*June 30, 2012 by Anonymous*

**physics**

a neutron of mass 1.67*1o power of (-27) is moving with a velocity 10 to the power of(6) collides with a deuteron of mass 3.34*10 to the power of (-27) kg at rest .after collision if both have single particle find its velocity
*April 11, 2012 by srikala*

**Chemistry**

The ionization energy of hydrogen is 1313 kJ/mol. Covert this energy to: wavelength (nm) 1/wavelength, reciprocal wavelength (cm^-1) spectral region? (IR, visible, UV, etc.) I know E=hv=hc/wavelength h=6.62 x 10^-34 J-s c= 3x10^8 v=c/wavelength But for some reason trying to ...
*December 7, 2012 by Sarah*

**Chemistry **

A 0.22-caliber handgun fires a 27-g bullet at a velocity of 765 m/s. Calculate the de Broglie wavelength of the bullet. Is the wave nature of matter significant for bullets?
*March 28, 2012 by danielle*

**Chemistry**

Im not exactly sure what how to solve this with the way my teacher asked this question. "For hydrogen atom transitions calculate E, v, and wavelength:" Ni= 1 li= 0 Mli= 0 Msi= -1/2 Nf= 2 Lf= 0 Mlf= 0 Msf= -1/2 E(kj)= ? v(Hz)= ? wavelength(m)= ?
*May 3, 2014 by Mary*

**chemistry 1**

How do you write balanced equations A. Neutron emission by 88Br B. Electron absorption by 116Sb C. Positron emission by 184Hg D. Alpha emission by 229Th E. Neutron capture by 200Hg
*October 25, 2013 by Alexus*

**Chemistry (Electrons in Atoms)**

The wavelength of visible light varies from 0.40 μm to 0.70 μm as the color of the light changes from violet to red. Calculate the energy of a photon whose wavelength is 0.67 μm HINT: From the wavelength and the speed of light, we can get the frequency. Then the...
*May 23, 2011 by Katie*

**Standing waves and resonance (physics)**

A nylon string has a linear density of 7.2g/m and is under a tension of 150N. The fixed supports are 90cm apart. The string is oscillating in the standing wave pattern. Find a)speed b)wavelength c) frequency v=sqr(F/u(linear density) v=sqrt(150N/7.2g/m) = 4.56m/s b) wavelength...
*February 6, 2007 by Susane*

**PHYSICAL SCIECE**

A seismic wave has a velocity of 5000 m/s and a frequency of 4Hz. wht is the wavelength of this wave? if this was a light wave traveling in a vacuum with the same wavelength, what would be its period?
*July 14, 2011 by CARLOS*

**chem**

the wavelength of ligh is 310 nm. calculate the frequency? what is the wavelength of electromagnetic radiation if its frequency is 3.2 X 10 -2(exponent) Hz??
*November 8, 2007 by Amanda*

**science waves**

how do you calculate the frequency when...when you do not know the wavelength...and same about finding wavelength when frequency is given????
*May 18, 2008 by ashley*

**Physics**

I need help solving this please! I think that for part (b) I can use energy and wavelength to solve for frequency and the one with the highest frequency is the most damaging, but I'm not sure what to do for part (a). You want to study a biological specimen by means of a ...
*August 15, 2010 by Brianna*

**Chemistry**

1.a radioscope which is neutron poor and very heavy is most likely to decay by? alpha , beta, electron capture, positron emission 2. When a 235-U nucleus is struck by a thermal neutron, fission occurs often with the release of neutrons. If fission fragments are 89-Sr and 144-...
*April 27, 2007 by keith*

**chem plz help!**

the rate of a nuclear reaction can be changed by?? i know adding a catalyst to a normal reaction can but to a nuclear im not sure. increasing temp decreasing pressure adding a catalyst none I suppose it all depends upon how you define a catalyst. Perhaps in a small way ...
*April 30, 2007 by luis*

**CHEM**

I just have a couple of questions that I need some help with: 1) A 0.22-caliber handgun fires a 27g bullet at a velocity of 765m/s. Calculate the de Broglie wavelength of the bullet. Express your answer using two significant figures in meters. ~and~ 2) An X-ray photon of ...
*November 5, 2007 by K*

**Chemistry**

Calculate the wavelength of light emitted when each of the following transitions occur in the hydrogen atom. (a) n = 5 n = 4 _________nm (b) n = 5 n = 3 _____________ nm (c) n = 5 n = 2 __________ nm Calculate the maximum wavelength of light capable of removing an electron for...
*October 20, 2008 by Giznelbell*

***physics***

Electrons accelerated by a potential difference of 12.87 V pass through a gas of hydrogen atoms at room temperature. Calculate the wavelength of light emitted with the longest possible wavelength. I don't know what equation to use. Any help would be greatly appreciated.
*March 24, 2008 by Beth Macbeth*

**Chemistry**

Can u show me how to calculate the neutron-to-proton ratio of an atom? For example: tin-134 or silver-107
*April 12, 2010 by Tammy*

**Neutron star-universal gravitational problem**

Hi, i'm having problem w/ this question...i've tried everything i know and i still don't get the right answer...here's the info they give: Consider a neutron star of mass M = 1.99e+30kg and a radius of R = 10 km. They ask 3 question...two of which i have answered (1st:...
*August 4, 2005 by Marcus Jasp*

**physics**

Find the threshold energy that the incident neutron must have to produce the reaction 1 n 0 + 4 He 2---> 2 H 1 + 3 H 1 For this, like the 1 n 0<--- it is supposed to be written like 1 on the top 0 on the bottom next to n. like the atomic number of neutron and the other ...
*February 16, 2007 by jaimie*

**Wavelength PLEASE HELP**

Calculate the wavelength of the signal sent by Q101 assuming that the actual frequency is 101.1 MHz. Determine how long it would take the signal to reach a car 33.4km away from the station. THANK YOU!
*May 22, 2013 by Mike Jones*

**physic**

Assuming uniform density, how much would 1.1 cubic centimeters of neutron star material weigh on the surface of the earth? You need the density of the neutron star to do this. weight= mass*g=density*volume*g
*May 23, 2007 by x*

**Physics**

Neutron stars consist only of neutrons and have unbelievably high densities. A typical mass and radius for a neutron star might be 5.8 x 1028 kg and 1.5 x 103 m. (a) Find the density of such a star. (b) If a dime (V = 2.0 x 10-7 m3) were made from this material, how much would...
*November 23, 2012 by StressedStudent*

**physics 1**

Neutron stars consist only of neutrons and have unbelievably high densities. A typical mass and radius for a neutron star might be 5.6 x 1028 kg and 1.5 x 103 m. (a) Find the density of such a star. (b) If a dime (V = 2.0 x 10-7 m3) were made from this material, how much would...
*April 22, 2014 by Anonymous*

**physics 1**

Neutron stars consist only of neutrons and have unbelievably high densities. A typical mass and radius for a neutron star might be 5.6 x 1028 kg and 1.5 x 103 m. (a) Find the density of such a star. (b) If a dime (V = 2.0 x 10-7 m3) were made from this material, how much would...
*April 22, 2014 by Anonymous*

**AP Chemistry**

A mixture of argon and mercury vapor used in advertising signs emits light of wavelength 610 nm. Calculate the energy change resulting from the emission of 1.00 mol of photons at this wavelength. Answer in units of kJ/mol.
*November 30, 2010 by Billy*

**Chemistry**

Heisenberg's uncertainty principle can be expressed mathematically as Δx*Δp = h/4π, where Δx and Δp denote the uncertainty in position and momentum respectively and h is Planck's constant. What would be the uncertaintry in the position of a neutron (...
*November 10, 2013 by Andy*

**Chemistry**

Atoms of ionized lithium gas (Li2+) are struck by neutrons moving at a velocity of 1.46e5 m/s. Calculate the shortest wavelength in the emission spectrum of Li2+ under these circumstances. You can assume that all electrons start in the ground state.
*March 22, 2013 by Sam Chem*

**Physics**

A motorboat is traveling 5m/s East, and encounters a current traveling 2.5m/s, North. If the witdth of the river is 80m wide, how much time does it take the boat to reach the other shore. I understand how to calculate the resulatant velocity, but I dont understand why you use ...
*October 20, 2010 by Jennifer *

**general physics**

Neutron stars consist only of neutrons and have unbelievably high densities. A typical mass and radius for a neutron star might be 6.3 x 1028 kg and 1.6 x 103 m. (a) Find the density of such a star. (b) If a dime (V = 2.0 x 10-7 m3) were made from this material, how much would...
*July 20, 2013 by please help with these practice problems*

**physics**

Calculate the magnitude of the electrostatic force the two down quarks inside a neutron exert on each other if they are separated by a distance of 0.71 fm.
*October 27, 2012 by melike*

**physics**

Green light has a wavelength of 4.96 10-7 m and travels through the air at a speed of 3.00 108 m/s. Calculate the period of green light waves with this wavelength. s What is the frequency? Hz
*March 12, 2011 by Jesse*

**physics**

Green light has a wavelength of 4.96 10-7 m and travels through the air at a speed of 3.00 108 m/s. Calculate the period of green light waves with this wavelength. s What is the frequency? Hz
*March 13, 2011 by Anonymous*

**physics**

For a particular type of wave in a particular medium why must f and lambda be inversely proportional. Frequency deals with the number of waves per second, while wavelength deals with the distance from peak to peak. It would be inversely proportional because lambda deals with ...
*February 18, 2007 by susan*

**science**

What is the wavelength of waves transmitted by an AM radio station operating at a frequency of 840 kilohertz? Calculate the energy of a photon whose frequency is 2450 megahertz What is the difference in energy for a photon of ultra-violet radiation, wavelength 319 nm and a ...
*December 5, 2012 by anna*

**Physics**

If a wavelength is doubled and velocity remains the same, is the frequency halved? I say "yes". If the velocity is halved and the wavelength remains the same, is the frequency halved. I say "yes" also. Am I correct?
*May 18, 2009 by NH*

**Chemistry**

What would be the speed of the following particles if they had the same wavelength as a photon of green light (λ = 500.0 nm)? Proton (mass = 1.673*10^(-24)g) =_____ neutron (mass = 1.675*10(-24)g) =_____ electron (mass = 9.109*10^(-28)g) =_____ alpha particle (mass = 6....
*April 2, 2013 by Anonymous*

**Chemistry**

What would be the speed of the following particles if they had the same wavelength as a photon of green light (λ = 500.0 nm)? Proton (mass = 1.673*10^(-24)g) =_____ neutron (mass = 1.675*10(-24)g) =_____ electron (mass = 9.109*10^(-28)g) =_____ alpha particle (mass = 6....
*October 10, 2013 by Natalie*

**Physics HELP!!**

1. What is the longest wavelength for standing sound waves in a 133.9cm long tube that is open at both ends? b).What is the second longest wavelength? c).What is the third longest wavelength? d).What is the longest wavelength for a standing wave, in the same length tube, that ...
*November 30, 2012 by joane *

**Physics**

NEED HELP On a flat battle ground, a catapult is used to launch a rock with a velocity of 25m/s at angle 30 degrees above the horizontal.? Sketch the situation and decompose the initial velocity vector. WHat are the initial values for Vx and Vy? Calculate the maximum height ...
*August 19, 2014 by Jeesha*

**Physics**

The following figure represents the ride for a cart with a mass of 200 kg along a frictionless track. a. Calculate the velocity of the cart at points A, B, and C if the cart is dropped from a height of 100m with a initial velocity of 10 m/s. b. Calculate the height of the ...
*July 25, 2014 by Liz*

**Chemistry**

1) Calculate the energy. in joules, of a photon of wavelength 1.250x 10^3 nm 2) If 3.011x 10^23 molecules have a mass of 20.04 grams, what is the molar mass of the substance? Is it 40.07g/mol? 3) 47.5g of Boron contains __________ atoms of B? Is it 2.65x10^24 4) What is the ...
*February 15, 2014 by Annabelle*

**chem**

What is the wavelength (in nm) of the line in the spectrum of the hydrogen atom that arises from the transition of the electron from the orbital with n =5 to the orbital with n = 2? Note, the line corresponds to the energy of the photon that is emitted in the transition. 4.34 ...
*October 26, 2012 by Anonymous*

**Physics**

A particle's initial velocity is given by vox = -1.0 m/s and voy = 3.0 m/s. Its acceleration is ax = 0.50 m/s^2 and ay = -0.90 m/s^2 (a) Calculate its velocity 2.0 s later. (b) Calculate its displacement at that time.
*October 4, 2009 by Sandhu*

**Physics**

Rank in order the following according to their speeds, from fastest (1) to slowest (5): (i) 425-nm-wavelength light through a pane of glass, (ii) 500-nm-wavelength light through air, (iii) 540-nm-wavelength light through water, (iv) 670-nm-wavelength light through a diamond, ...
*February 2, 2013 by Cassie*

**Chemistry**

An electron ps from the 6th to te 3rd energy level in the hydrogen atom: a) calculate the wavelength b) calculate the frequency c) calculate te enrgy d) into which spectral series would the photon be grouped? (i really just need to formulas, then i could solve myself...)
*May 23, 2011 by Ella*

**chem**

Among the elementary subatomic particles of physics is the muon, which decays within a few nanoseconds after formation. The muon has a rest mass 1.126 109 times that of a proton. Calculate the de Broglie wavelength associated with a muon traveling at a velocity of 3.35 104 cm/s.
*November 14, 2012 by Samantha*

**college Chemistry**

It requires 945.0 kJ/mol to break N2 molecules into atoms. Calculate the maximum wavelength of light that will still break these molecules apart. I tried converting the energy to kj and using E=hc/wavelength but that didn't give me the right answer...
*November 4, 2010 by alexis*

**college Chemistry**

It requires 945.0 kJ/mol to break N2 molecules into atoms. Calculate the maximum wavelength of light that will still break these molecules apart. I tried converting the energy to kj and using E=hc/wavelength but that didn't give me the right answer...
*November 4, 2010 by alexis*

**Science - Waves - Sci. Notation**

I know that the formula to calculate the speed of light is c=fλ. F is the frequency, c is the speed, and λ is the wavelength. So how do I calculate the wavelength of a purple light with a frequency of 750 * 10^12 HZ. Frequency is measured in HZ. The speed is measured...
*January 31, 2013 by Jamia*

**Physics**

A wave has an amplitude of .25m, a wavelength of .68m and a frequency of 3.2 hz. Find it's velocity? To solve I just used v=3.2 * .68=2.176m/s because amplitude doesn't factor into velocity. Is this right?thanks.
*May 14, 2009 by NH*

**Physics Help**

A graph of wavelength vs. 1/frequency should be a straight line. What are it's slope and y-intercept? I'm not given any graphs or numbers, just this question. And I know that Velocity = frequency x wavelength And that slope is found by rise/run and m= y2-y1/x2-x1 obviously. So...
*April 3, 2014 by Eiban*

**Chem**

Hello What is the wavelength (in nm) of the line in the spectrum of the hydrogen atom that arises from the transition of the electron from the orbital with n =5 to the orbital with n = 2? Note, the line corresponds to the energy of the photon that is emitted in the transition...
*October 26, 2012 by Anonymous*

**math**

can please somebody check my answer: Q. A tuning fork produces a sound that has a wavelength of 136 centimetres. What is the frequency of the tuning fork? (Take the speed of sound to be 340 metres per second.) A. f= velocity/wavelength f= 340/1.36 f=250Hz
*July 15, 2011 by Roger*

**chemistry**

one reason carbon monoxide(CO) is toxic is that it binds to the blood protein hemoglobin more strongly than oxygen does. The bond between hemoglobin and CO absorbs radiation of 1953 cm^-1. (the units are the reciprocal of the wavelength in centimeters). Calculate the ...
*October 13, 2008 by kelsie*

**Physics**

Electrons are ejected from a surface with speeds ranging up to 6.0 x 10^5 m/s when light with a wavelength of 400 nm shines on it. a.) What is the work function of this surface? b.) What is the threshold frequency for this surface? c.) What is the deBroglie wavelength of an ...
*June 12, 2006 by Nathaniel*

**chemistry**

if the wavelength of the first line in the balmer series in a hydrogen spectrum is 6863A .calculate the wavelength of the line in the lyman series in the same spectrum
*August 17, 2014 by Anonymous*

**physics -- fluid mechanics**

Neutron stars consist only of neutrons and have unbelievably high densities. A typical mass and radius for a neutron star might be 3.4 multiplied by 1028 kg and 2.0 multiplied by 103 m. (a) Find the density of such a star. (b) If a dime (V = 2.0 multiplied by 10-7m3) were made...
*November 30, 2008 by cindy*

**physics (Newton's Law of gravitation)**

I need help with this question until the end if you can, please. Thank you. A neutron star and a black hole are 2.400e+12 m from each other at a certain point in their orbit. The neutron star has a mass of 2.78×10^30 kg and the black hole has a mass of 9.94×10^30 kg. What is ...
*April 22, 2013 by Kathy PLEASE HELP*

**College Chemistry (Hard)**

The easiest fusion reaction to initiate is 1-1H + 1-1H------> 4-2He + 1-0 n The 1-1 indicates a small one above the other on the left side of the symbol of the element.So for 1-0n is a one above a zero on the left side of n (neutron). The number on the top is the atomic ...
*April 5, 2010 by Jim*

**physics**

An example of the neutron absorption reaction is . 1 0 n+10 5 B-->7 3 Li+ 4 2 He The rest masses of each particle in atomic mass units (u) are 1 0 n= 1 u 10 5 B=10 u 7 3 Li =7 u 4 2 He= 4 u where 1u=1.66x10^-27 kg. calculate Q Q= in MeV I have the same question please ...
*May 8, 2013 by Amy*

**physics**

there's a equation for wavespeed=wavelength*f the wavespeed doesn't depend on the wavelength. Why not? if you double the wavelength, won't the speed increase as well. In my book, it says that v is unchanged. I don't understand
*July 8, 2009 by Anonymous*

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