What are two molecular states ?

[xylai]

In molecular orbital theory, there are two molecular states. (see below)

I don't know the differences between these two states?

 

[alxm]

The difference is one of them has an apostrophe.

Seriously though, to my knowledge there's no system of notation for atomic or molecular orbitals which uses the prime symbol for anything in particular. I'm guessing in the context they're denoting a particular atom's 1s orbital with a prime and another's without.

Writing [tex]\sigma_g1s[/tex] doesn't quite make sense by itself either - sigma is an MO, 1s is an atomic orbital, and you need at least two of those to get an MO.

[tex]\sigma_g[/tex] signifies the even (gerade) symmetry, it's the same as the bonding sigma orbital.

 

[charng]

The two molecular states refer to the bonding and anti-bonding states in molecular orbital theory. These states represent the distribution of electrons in a molecule and are determined by the combination and interaction of atomic orbitals. In the bonding state, the electrons are shared between the atoms, resulting in a stable and lower energy state. In the anti-bonding state, the electrons are pushed away from each other, leading to an unstable and higher energy state. The main difference between these two states is the distribution of electron density and energy levels. Understanding and analyzing these states is crucial for predicting the properties and behavior of molecules in chemical reactions.