## Wavelengths I NEED to know for the exam. In terms of unit 3, part 1.

### herbeey

Posted 23 March 2005 - 09:36 PM

Ahem.

hur!

### Steve

Posted 23 March 2005 - 10:05 PM

It would be helpful if you could be a bit more specific.

### herbeey

Posted 23 March 2005 - 11:22 PM

For unit 3, part 1... about the light, and about how different wavelengths of colour of light order themselves... something like that.
I remember being told that it's necessary to know 2 or 3 for the exam.
I think it's the wavelengths for red and violet, but this is why I ask.

### broughy

Posted 23 March 2005 - 11:36 PM

yeah, we were told to know the wavelengths for red, green & blue light. can't for the life of me remember what they are though!

### werlop

Posted 24 March 2005 - 04:13 PM

### herbeey

Posted 24 March 2005 - 11:19 PM

Cheers for that.
Although, I remember my summary notes telling me to learn 420, while something else told me to learn something like 470... does it matter, or could I be okay with just 400 (times ten to the minus seven)

### werlop

Posted 24 March 2005 - 11:47 PM

Just learn the general trends of the electromagnetic spectrum. In the visible light section you have violet at the 400 nm end and red at the 700 nm end. Yellow is in the middle. From that you can approximately work out values. There is no point in remembering that blue is such and such a wavelength, as afterall, what is blue? There are so many shades!

If asked I would quote four hundred and something nanometers for blue.

### broughy

Posted 24 March 2005 - 11:59 PM

according to my chemcord revision book for higher physics (which is what i'll have been taught in class, since the teacher that wrote the book is head of physics at my school!), wavelengths are:

red light: 700nm
green light: 540nm
blue light: 490nm

### herbeey

Posted 25 March 2005 - 09:58 PM

sub question; Is blue considered to be violet in questions, and therefore having the wavelength of violet? In other words; is blue and violet interchangeable?