The smallest type of nucleus is the nucleus of an h atom. And so what that means is this H atom, because it's so small, it can actually get very close to that oxygen atom. And if it gets very close, the distance decreases. And we know that our electric force is directly or inversely proportional to the square of the distance between our two charges. And so because the distance here will be so small. If the distance is small, the force will become large.