A transformation in which one or more substances is converted into another by combination or decomposition.
An action or statement in response to a stimulus or other event.
An icon or emoji appended to a posted message by a user to express their feeling about it.
Reactionary politics; a period in which reactionary thought or politics is resurgent or dominant.
An amount or power (especially electric), expressed in watts, kilowatts etc.
The power requirement of some electric appliance.