# Homework Help: Basic Chemistry problem

1. Feb 15, 2005

### maxpayne_lhp

Well, hello!
I was informed a new formula. As a non-native, I can't give out the definitons, I hope that you can help me call some.
Well, here is the formula:
$$\Delta=\frac{2+\Sigma n_i (V_i-2)}{2}$$
Well, as far as I can say, $$\Delta$$ here is equal to the total of the linkage C=C+ number of 'cycles' in my language?
So, what is this for and how was it formed? I really want to know so that I can apply to my problems.
Thanks for your time and help!

2. Feb 15, 2005

### maxpayne_lhp

Ah, by the way, We have:
If $$\Delta =0$$, the subtance is not 'full' so; it has no $$\pi_{cc}$$ linkage, no 'cycle.
If $$\Delta =1$$, the subtance has 1 $$\pi_{cc}$$ linkage OR 1 'cycle'
If $$\Delta =2$$, the subtace has 2 $$\pi_{cc}$$ linkages OR 1 $$\pi_{cc}$$ linkage + 1 'cycle' OR 2 'cycles'
So, what is this all about?
Thanks again!