2.3.1

When a sample of matter undergoes a physical change,its chemical composition,or the arrangement of its atoms or ions does not change.A piece of aluminum foil cut into small pieces is still aluminum foil.When solid water (ice) melts or liquid water boils,none of the H2O molecules are changed;instead,the molecules are organized in different spatial (physical) patterns.

當樣品的物質進行物理變化，其化學成分，或安排其原子或離子不改變.一片鋁箔切成小塊，仍然是鋁.當固態水（冰）融化或液態水歸根結底，沒有水分子改變，而是有組織的分子是在不同的空間（物理）模式。