# How to pronounce this term symbol?

1. Jul 26, 2015

### td21

$$5^{2}S_{\frac{1}{2}}$$
My guess is five-two-S-one-over-two. Any suggestion is appreciated. Thanks.

2. Jul 27, 2015

### blue_leaf77

We usually pronounce your "one-over-two" as "one-half".

3. Jul 27, 2015

### Staff: Mentor

In what branch of science does this expression come from?

Absent further details, I'm tempted to say $5^2$ is pronounced "five squared".

4. Jul 27, 2015

### blue_leaf77

I believe this is from the so-called term symbol for the state specification of many-electron atom.

5. Jul 28, 2015

### nasu

The 5 is not squared, 5 and 2 have different meanings.
See here for example
http://www.astro.sunysb.edu/fwalter/AST341/qn.html

I think pronunciation is not really relevant. You don't communicate these things verbally.

6. Jul 28, 2015

### Khashishi

Why is there a 5 in front? As far as I know, the term symbol shouldn't have a 5 in front.

7. Jul 28, 2015

### nasu

I thought that the 5 is out of place too.
But that link seems to suggest a quantum number n that goes in front.

8. Jul 28, 2015

### blue_leaf77

That's indeed uncommon, but probably that indicates that the valence shell, which is the only one incomplete, corresponds to n=5.