Chemistry Help!!!!! Need help on 2 problems....?

**sportegirl7** · 07-12-2009, 06:13 AM

here they are
1) What is the wavelength of an electromagnetic wave that travels at 3x10^8 m/s and has a frequency of 60 MHz? (1 MHz= 1,000,000 Hz).

2) What is the approximate frequency of a photon having an energy 5x10^-24 J? (h=6.6x10^-34 J-s).

i would appreciate it if you showed me how to do it like step by step and like what formula to use.. thanxx!!!

07-12-2009, 06:13 AM

This should be in physics.

1) use wavelength = velocity(speed) / frequency. Watch your units must all be in metres and hertz, remove any megas etc

2)use planks equation: Energy / planks constant = frequency
Planks contrant = 6.626â€‰) Ã— 10âˆ’34 Js-1

**Sean** · 07-12-2009, 06:20 AM

1) Wavelength, velocity, and frequency are related by v = Î»f so solve for Î» = vÃ·f:

Î»= (3 x10^8) Ã· (6.0 x10^7) = 5m

#2) You're given energy, E, and h = Planck's constant. The equation you need to use is E = hv where v = frequency. Solve for v = EÃ·h:

v = (5.0 x10^-24) Ã· (6.6 x10^-34) = 7.6 x10^9Hz or 7.6 GHz