Which substrate might produce optically different products upon reaction with an alkyl halide depending on whether an SN1 or SN2 mechanism predominated

☆ionisation energy increases across a period from na -> ar☆ionisation energy decreases down a group from li -> fr☆ionic radius decreases across a period from na -> cl☆ionic radius increases down a groupfrom f -> ii hope it clarifies your doubts

Ibelieve its because the stove is a cleaner burning fuel