Question

ice molecules take up more volume than liquid water molecules. which of these conditions occurs when water in a pond freezes?
water molecules solidify at the bottom and push the liquid water upward.
water molecules solidify near the surface and float on the liquid water.
water molecules break apart into solid oxygen and solid hydrogen.
water molecules form solids when they combine with dissolved minerals.

Explanation:

When water freezes, it forms ice. Ice is less dense than liquid water. This is because the hydrogen - bonding in ice creates a more open, hexagonal lattice structure. As a result, water molecules solidify near the surface (where the temperature drops first) and float on the liquid water. This is a unique property of water.

• Option 1: Water molecules do not form solids when combining with dissolved minerals during freezing. Freezing is a phase change of water molecules themselves, not a combination with minerals in this context.
• Option 2: Water molecules do not break apart into solid oxygen and solid hydrogen. Water is \(H_2O\), and freezing is a physical change, not a chemical decomposition.
• Option 4: Water molecules solidify at the surface (not the bottom) first because heat loss (which causes freezing) usually occurs at the surface - air interface.

Answer:

Water molecules solidify near the surface and float on the liquid water.