LESSON 3 Sink and Float

Mr. Moreno put some objects in a pan of water. Some of the objects sank to the bottom. Others floated. “What makes an object sink or float?” asked Mr. Moreno.

“I think heavy things sink and light things float. So, I think an object's mass is the reason things sink or float,” said Nicholas.

“I think big things sink and little things float. So, I think volume is the reason things sink or float,” said Jackie.

“But ships are big and heavy. Why do they float?” wondered Luis.

In this activity, you will explore the reasons why things sink or float. Before you begin, discuss what properties of an object you think determine whether it will sink or float.