Note: If you are forming a new bond, the electron-flow arrow should point to between the two atoms, not to one of the atoms. Specifically, click and hold on the bond or atom that is the source of the electrons, drag the cursor along the line between the two atoms where the new bond will be, and release when you see blue parentheses around the two atoms and a dashed line between them. (The atoms must initially be beyond bonding distance.)

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