Baking soda has only one ingredient: sodium bicarbonate, is a leavening agent, used to produce a gas that makes baked goods raise.
Recipes using baking soda uses an acid (liquids like vinegar, milk,molasses, honey; or dry like cream of tartar.
Baking soda releases this gas all at once so you do not want to let a batter sit around too long or beat it too much.If you do, the leavening action will be lost and your baked goods will fail to raise.