Have you ever stumbled upon a simple picture puzzle and thought, “Oh, this is going to be easy”?
Take a look at the image above: on the left, we have a glass filled with liquid water, and on the right, a glass filled to the brim with ice cubes.
At first glance, both glasses look pretty full and equally balanced.
So, which glass do you think is actually heavier?
Before you jump to a quick conclusion, let us break down the science behind it in a simple way.
Many people automatically pick the glass of ice because ice cubes take up a lot of space and look bulky.
Others choose the glass of water because liquid feels heavier and denser when you hold it.
To solve this riddle, we need to understand how ice and water behave differently in terms of density and space.
Density simply means how tightly packed the tiny particles are inside an object.
When liquid water freezes into ice, the water molecules expand and arrange themselves into a rigid crystal structure.
This expansion means that ice takes up more volume, or space, than the same amount of liquid water.
Because ice expands, it becomes less dense than liquid water, which is why ice floats in your drink!
Now, let us look at the contents inside both glasses.
The glass on the right is filled with solid ice cubes, but there are empty spaces or air gaps trapped between those uneven cubes.
Because of these air pockets and the lower density of ice, the total amount of actual water material in the ice glass is less than it appears.
On the other hand, liquid water flows freely and completely fills every tiny corner of its glass without leaving any air gaps.
If you were to let the ice glass melt completely at room temperature, you would notice something interesting.
The melted ice would turn into liquid water, but it would not fill the glass all the way to the top like the first glass.
Instead, the water level would drop significantly because the air gaps vanish and the expanded ice shrinks back into compact liquid form.
This proves that the first glass contains a larger total mass of water overall.
Since both glasses are identical in size and shape, the total weight comes down strictly to the content inside them.
More water content simply means more mass, and more mass means more weight on a scale.
Therefore, the correct answer is 1. Glass of water.
The glass filled with liquid water is heavier than the glass filled with ice cubes!
