Now, since this orbital is lower in energy, that means our electron pair coming from this highest occupied molecular orbital goes directly into this bonding molecular orbital. So let's look at a few more examples. Now, let's suppose we have example a. In this reaction, we have a hydroxide with a negative sign interacting with a sodium ion with a positive sign, and we form sodium hydroxide. So which one has the homo and which one has the lumo? So clearly, this is our base.