What are 10 things that sink in water?

What Sinks in Water — And Why

Ever dropped a pebble into a pond and watched it vanish beneath the surface? That’s sinking in action. Whether it’s a heavy rock or a forgotten fork at the bottom of a lake, some things just don’t stand a chance against water’s embrace.

The reason certain objects sink comes down to density. If something is denser than water—about 1 gram per cubic centimeter—it will sink. Water resists less dense materials, like wood or plastic, but it can’t hold up heavier ones.

Rocks and stones top the list. Their compact mineral makeup makes them denser than water, so they plunge straight down. Metals like iron, lead, and copper are even more predictable—they almost always sink. Think of a cast-iron skillet or a lump of copper wiring.

Other everyday items include coins (usually made of dense alloys), keys (often brass or steel), scissors, hammers, ceramic plates, and even a solid glass bottle. Even some types of fruit, like unripe persimmons, can sink if they’re dense enough.

Interestingly, shape doesn’t always save an object. A metal ship floats because it’s designed to displace a lot of water, but a solid iron ball of the same weight would plummet. It’s not just weight—it’s how that weight is distributed.

So next time you're by the water and toss something in, ask yourself: will it sink or float? The answer lies in what it’s made of, not how big or small it looks. Density rules the waves.