CHEMISTRY COMMUNITY

In the textbook it says that h bar in the uncertainty equation is equal to h/2pi. However, in our notes it says that the hbar formula is h/4pi. Which are we supposed to use?

The more correct one to use is the h/4pi.

The formula given during lecture for Heisenberg's Indeterminacy Equation utilized h rather than h bar. It read (delta p)(delta x) is greater than or equal to (h/ 4pi). In the textbook, instead of using (h/4pi), they described the equation in terms of (h bar/2) which is actually equivalent since h bar is equal to (h/2 pi). Therefore, (h/4 pi) and (h bar/2) are both correct.

I don't think it matters which one you use, as long as you know that the original equation is h/4pi. The h bar symbol is just used as a shorthand really for h bar = h/2pi, so it's up to you.

Since h bar is equal to (h/2π) it's very useful as shorthand where this value is used often like in Heisenberg indeterminacy equation and the Schrodinger equation. In the Heisenberg equation, the (h-bar/2) is equal to (h/4π) in case you come across the equation using h-bar.