Question

when water (h₂o) freezes into ice, some of the properties have changed. what stays the same?
identity of the h₂o
energy of the h₂o
arrangement of the h₂o
property of the h₂o

Explanation:

Freezing of water is a physical change. During a physical change, the chemical identity of the substance remains the same. Water ($H_2O$) in liquid and solid (ice) states is still $H_2O$. Energy changes as heat is released during freezing, the arrangement of $H_2O$ molecules changes from a more disordered liquid - state arrangement to a more ordered solid - state lattice, and some physical properties like density and state change.

Answer:

identity of the $H_2O$