Question

melting butter is a physical change. which best describes what is happening?
the butter changes into a different substance.
the butter contains a new arrangement of atoms.
the butter cannot turn into a solid again.
the butter no longer contains the same number of atoms.

Explanation:

A physical change involves a change in the state or appearance of a substance without altering its chemical composition. When butter melts, it changes from a solid to a liquid. The atoms or molecules of butter remain the same; there is no new substance formed (so the first option is wrong). In a physical change, the number of atoms remains constant (so the fourth option is wrong). Also, melted butter can solidify again (so the third option is wrong). A physical change can involve a change in the arrangement of atoms/molecules (e.g., from a more ordered solid - state arrangement to a less - ordered liquid - state arrangement).

Answer:

The butter contains a new arrangement of atoms.