A hole is drilled to the center of the earth and a ball is dropped into it. When the ball is at the earth's center, compared with their respective values at the earth's surface,

At the center of the earth if the ball is dropped in the hole then it's mass will be the same but the weight of the ball will be zero. As the gravity at the center of earth will be zero. As,

W = mg

However at the surface of earth the ball will have the maximum weight.