Default arrow setting. It is also a combo button: further arrow types can be selected from a sub-menu, after clicking on the black triangle in the lower-right corner of the button.
It is also a Smart (multifunctional) tool:
What kind of arrows are available in Marvin JS?
|Reaction arrow symbol||Reaction arrow type|
|Two-headed arrow (Resonance arrow.)|
How to put a "+" sign onto the canvas:
Select the Reaction tool, then left-click onto the canvas where you would like to place the "+" sign.
How to put an arrow onto the canvas:
Select the Reaction tool, then drag with it on the canvas where you would like to place the arrow. During the dragging a gray feedback shows the future position of the newly forming arrow. Release the button to create the arrow.
If it is necessary the length and the direction of the arrow can be changed afterwards.