## anonymous one year ago Calculate the de Brolie wavelength (in nm) of a hydrogen atom (m=1.674 x 10^-27 kg) moving at 1430 cm/s.

1. anonymous

do you know de brogile's formula?

2. anonymous

Not really

3. anonymous

$$\sf p=h/ \lambda$$? p=momentum, h=planck's constant, lambda=wavelength.. rearrange the formula to solve for the wavelength: $$\sf \lambda =h/p$$ you know that momentum is equal to mass times velocity so sub p=mv to the equation.. it will be $$\sf \lambda =h/mv$$ Sub in your given values, just be careful about the units though :)

4. anonymous

do you know the value for Planck's constant?

5. anonymous

yes. 6.626 x 10^-34

6. anonymous

don't forget the unit, it is very important

7. anonymous

(6.626x10^34 kg m^2/s^2 s)/(1.674x10^-27kg)(14.3m)

8. anonymous

**it should be 6.626x10^34 kg m^2/s and 14.3 m/s kg, m, and s will get cancelled out, so your answer would be in metres, what will you get when you calculated that?

9. anonymous

1586145132 m

10. anonymous

11. anonymous

try recalculating it again.. |dw:1443058593861:dw|

12. anonymous

I got that answer when I did it again to double check.

13. anonymous

Got 2.767983959x10^-8

14. anonymous

Is that what you got?

15. anonymous

okay, i think we got the same answer now. Last thing you have to do is to convert that to nm

16. anonymous

I multiple by 1.0 x 10^-9 right?

17. anonymous

yeah.. but i think it should be 1x10^9 nm because you're going from m to nm If you are converting from nm to m, then it will be x10^-9

18. anonymous

I got 27..67983959

19. anonymous

*27.6798359