Rated with a scale number from 0 to 14, 7 is considered to be neutral, less than 7acid in nature, and greater than 7 alkaline.

• 用一个由0到14的数字尺度计算，7是中性，少于7是酸性，多于7的是碱性。纸张或水槽的酸碱程度就用它表示。