ACTIVITY SHEET SCIENCE BEHIND SINK OR FLOAT When objects are placed in water, they will either sink, or they will float. If something sinks, that means it goes down beneath the surface of the water, and when something floats, that means it rests on or near the surface of the water. Whether an object sinks or floats, doesn’t have as much to do with its weight as it does with its density. Everything around us is made up of tiny molecules. How closely these molecules are packed together determines its density. Objects with molecules packed very close together are always going to be more dense than those with the molecules packed loosely.
KEY TERMS Buoyancy - the ability or tendency to float. Density - the degree of compactness of a substance. Molecules - a group of atoms bonded together. Object - a material thing that can be seen and touched. Pressure - continuous physical force exerted on an object by something in contact with it. • Surface - the outside or uppermost layer of something.
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