If the double bond is broken heterolytically, formal charge pairs result, as shown in the other two structures. The preferred charge distribution will have the positive charge on the less electronegative atom (carbon) and the negative charge on the more electronegative atom (oxygen).
Single malt Scotch. Single malt Scotch is single malt whisky made in Scotland. To be a single malt scotch the whisky must have been distilled at a single distillery using a pot still distillation process and made from a mash of malted grain. In Scotland, the only grain allowed to be used in a single malt whisky is barley.
A Single Malt is a whisky made from malted barley in one distillery. A Pure Malt is a whisky made from malted barley. This appellation has no official character, and can be used as well for whisky from one or more distilleries. A Vatted Malt is a whisky made from malted barley, and is a mix of single malts from different distilleries. A Blended Whisky (blend) is a mix of malt whisky (generally from different distilleries) and grain whisky. (not malted) I think the closest thing to a double malt is a blended whisky