Textbook 1A.9

$E=hv$

Vivian Hoang 1H
Posts: 98
Joined: Wed Sep 30, 2020 10:09 pm

Textbook 1A.9

Hi everyone!

I was working on number 9 and can't figure out the 4th row of the table. I keep getting different answers than the solutions manual. Can anyone explain step by step with the numbers inputted? Please and thank you!

"A college student recently had a busy day. Each of the student’s activities on that day (reading, getting a dental x-ray, making popcorn in a microwave oven, and acquiring a suntan) involved radiation from a different part of the electromagnetic spectrum. Complete the following table and match each type of radiation to the appropriate event:"

The value given is 2.5nm (wavelength.) You are looking for the Energy of the photon and frequency.

connie ma 3G
Posts: 94
Joined: Wed Sep 30, 2020 9:38 pm
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Re: Textbook 1A.9

First convert the wavelength to m: 2.5 nm = 2.5 x 10^-9 m

Then use c=(lambda)(v) to solve for frequency. It should look like 3 x 10^8 = (2.5 x 10^-9)(v) You should get 1.2 x 10^17 Hz

Then use the frequency you just calculated to find the E with E=hv. It should look like E = (6.63 x 10^-34)(1.2 x 10^17) You should get around 7.9 x 10^-17 J (or 8.0 x 10^-17 if you rounded it up)

This frequency is in the x-ray region.

Vivian Hoang 1H
Posts: 98
Joined: Wed Sep 30, 2020 10:09 pm

Re: Textbook 1A.9

Ahh, I mixed up my equations.. thank you so much!