## CALM: Chapter 7, Problem 8; Chapter 8, Problem 3.greenspun.com : LUSENET : UR General Chemistry : One Thread |

For CALM problem #8 in chapter 7, it asks us to find deBroglie wavelength for an alpha particle. deBroglie's equation for wavelength states that wavelength = h / (mass * velocity). The problem gives us the energy (4.4 MeV), but not the velocity. Do we know the velocity of an alpha particle?Also, for problem #3 in chapter 8, the second part of the question asks us what group our element is in. I had Nickel. Yet, CALM did not accept my answers which included "transition metal," "metal," "10" (nickel's group number). I don't know what CALM is exactly asking for when they ask what group our element is in. Maybe someone who has done the problem can help out?

Thanks.

-- Anonymous, April 12, 2000

Hey Justin! ok, about #3 of topic 8...when they ask for what group the element is in, they want to know if they're in group 1A, 2A, 3A, 4A and so on. However, since nickel is in the section of transition metals, you won't know what group it's in. The book say (and I quote), " the meaning of the group labels for the transition metals is not as clear as for the A group elements, so these will not be used in this text." Therefore, you will not find te group for transition metals in the book. So I suggest you do a different problem, where you get an element that is in one of the A groups.About #8 in topic 7, what I did was convert MeV to Joules (1MeV = 1 x 10^6 eV and 1 eV = 1.602 x 10^-19 J) and then using the equation E = hv, I solved for v. Then using this v, use the equation wavelength = h/(m*v) to solve for wavelength. I think that's how you do it. I haven't actaully tried it myself but hopefully it'll work.

-- Anonymous, April 12, 2000

Try Group 8 for Nickel....I think that should work. If not, just try a different version of the problem.

-- Anonymous, April 12, 2000

PLEASE DISREGARD ANYTHING I SAID ABOUT #8 in TOPIC 7, IT WAS TOTALLY WRONG...the correct way to do it is use the equation E = (1/2)*m*v^2 to solve for velocity and then use wavelength = h/(m*v) to solve for wavelength. This is how you do it.

-- Anonymous, April 12, 2000

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