How did scientists conclude that most of an atom is empty space?

From the graph the speed of the snail in the first 20 seconds centimeter/second. after that, the snail remains in the same place for seconds

Find the vertex(use the completing the square method), findthe x- and y-intercepts, and sketch the graph offunction. y = 2x2 + 4x - 1

25pts the diagram shows the positions of the sun, moon and earth during spring tides, when the high tides are at their highest and low tides at their lowest. what is it about these positions that causes these high and low tides?