On Facebook.com, hover the mouse over the Like icon. A pop-up box of reactions appears above it. In the mobile app, long press the Like icon to trigger the reactions to pop up. To see a breakdown of ...

Researchers developed a machine-learning model that can predict the structures of transition states of chemical reactions in less than a second, with high accuracy. Their model could make it easier ...

Penn State researchers have uncovered a surprising twist in a foundational chemical reaction known as oxidative addition. Typically believed to involve transition metals donating electrons to organic ...

This article explains how to use reactions on the Facebook website and mobile app. How to Use Reactions on Facebook.com Here's how to apply a reaction to a post: Pick a post that you want to react to.