Recent content by doubleB

Can anyone help me?

Homework Statement I've attached a J-peg with the question in, laid out much more clearly than I could expect to type it here. I hope the attachment is ok. Homework Equations The Attempt at a Solution So far I have: (1) dS = dQ / T Entropy is a measure of a system's...

My question says: "Evaluate the expectation value <1/r> of the 1s state of hydrogen. How does this result compare to the result found using the Bohr theory?" Firstly, I have been told that <1/r> does not mean <1/r> but rather that it means 1/<r>. Having made it this far I now do the 1/<r>...

Thanks to everyone for the help; I think I'm starting to understand it. To Russ: I'm just slightly confused about what you said to Ideologue - you said that 14psi is actually a lot, like 2500lb of bricks stacked on your chest. But you then said that 14.7lb per square inch is less than clapping...

It's just that the way I see it is that if there are billions of tonnes of air on us then although most of our bodies wouldn't compress, because it's water, some bits would? I think I just don't understand what is going on...Is the air actually pounding down on us? And I mean if a million tonne...

What do you mean?

Why doesn't the sky crush us all?? I'm sure I've thought this through before but after an afternoon wondering I need to ask: Why is it that the billions of tons of air above us doesn't crush us? Thanks for the help!

Nrged: The formula I got from a page of printed notes from one of my lecturers, it could easily have been wrong I think as they seem to make mistakes often. When you wrote earlier that e(-m) = -1(m) * e(m), were you saying e to the power of minus m = etc etc? Are they all to the power of? Thanks...

Thanks everyone for the help. Much appreciated. Just one thing - I'm being a bit stupid - how does e(-m) = -1(m) * e(m) ? DoubleB

Oh right. I think the R I'm using is R with a subscript infinity. Does that change anything?

Thank you, I looked around some more and saw that when they say the 'Red Balmer Lines' that is like saying the 'H-alpha Balmer Lines'. The only thing I'm very unsure about is that in my notes it says: En = -R / n2 This formula is right isn't it? This is confusing me a lot...

I forgot to say "red alpha Balmer Lines".

Hi again, Could someone explain a tiny bit about Balmer Lines to me? If I was asked what is the difference between the red Balmer Lines in Hydrogen and Deuterium, where would I begin? How do I know which energy level the electrons are in? If it's a red Balmer Line then I guess n = 2 for...

I've attached the formula as a word document because I think if I try to type it I'll mess it up... Ok I tried to attach it but apparently it's too big so here goes: Spherical Harmonics: The complex conjugate of Y(l,m) = -1 to the power of m MULTIPLIED BY Y(l,m). Is this right? I...

Oops, just noticed I typed extensive again in that post before! Yep, pressure's intensive.